Jack Boyd

All Publications

• Heart-Liver Transplantation Utilizing the En Bloc Technique: A Single-Center Experience Over Two Decades. The Journal of thoracic and cardiovascular surgery Mullis, D. M., Garrison, A., Heng, E., Zhu, Y., Elde, S., Nilkant, R., Boyd, J., Hiesinger, W., Lee, A., Shudo, Y., Gallo, A., Bonham, C. A., Woo, Y. J., MacArthur, J. W. 2024

  Abstract

  Combined heart-liver transplantation (CHLT) is a definitive therapy reserved for patients with concomitant heart failure and advanced liver disease. A limited number of centers perform CHLT, and even fewer use the en bloc implantation technique. This study 1) reviews clinical outcomes and immunoprotective effects following CHLT, and 2) describes our institution's experience of over two decades using the en bloc technique.All patients who underwent CHLT at our institution between January 2003 and July 2023 were identified. Recipient and donor characteristics, operative details, and clinical outcomes were assessed. Kaplan-Meier analysis was performed to evaluate survival following CHLT.A total of 20 patients underwent CHLT using the en bloc technique at our institution between January 2003 and July 2023. At a median follow-up of 3.8 years for patients who survived the perioperative period (n=18), estimated survival at 1- and 5-years was 94% and 75%, respectively. There was 100% freedom from acute moderate rejection, acute severe rejection, and chronic rejection in all patients. No patients required re-transplantation due to rejection.CHLT is a definitive therapy reserved for patients with multi-organ dysfunction. At our institution, the en bloc technique is the preferred operative approach, as it minimizes cardiac insult, requires fewer anastomoses, minimizes cold ischemia time, and allows for rapid correction of coagulopathy. Overall survival for this cohort is excellent. Episodes of acute rejection were rarely observed, providing further support that the liver may serve an immunoprotective role in multi-organ transplantation.

  View details for DOI 10.1016/j.jtcvs.2024.08.031

  View details for PubMedID 39187122

• Impact of American Heart Association Awards on the Academic Careers of Cardiac Surgeons. Journal of the American Heart Association Bajaj, S. S., Wang, H., Kumar, S. S., Williams, K. M., Boyd, J. H. 2024: e034541

  View details for DOI 10.1161/JAHA.124.034541

  View details for PubMedID 39041656

• Personalized coronary and myocardial blood flow models incorporating CT perfusion imaging and synthetic vascular trees. Npj imaging Menon, K., Khan, M. O., Sexton, Z. A., Richter, J., Nguyen, P. K., Malik, S. B., Boyd, J., Nieman, K., Marsden, A. L. 2024; 2 (1): 9

  Abstract

  Computational simulations of coronary artery blood flow, using anatomical models based on clinical imaging, are an emerging non-invasive tool for personalized treatment planning. However, current simulations contend with two related challenges - incomplete anatomies in image-based models due to the exclusion of arteries smaller than the imaging resolution, and the lack of personalized flow distributions informed by patient-specific imaging. We introduce a data-enabled, personalized and multi-scale flow simulation framework spanning large coronary arteries to myocardial microvasculature. It includes image-based coronary anatomies combined with synthetic vasculature for arteries below the imaging resolution, myocardial blood flow simulated using Darcy models, and systemic circulation represented as lumped-parameter networks. We propose an optimization-based method to personalize multiscale coronary flow simulations by assimilating clinical CT myocardial perfusion imaging and cardiac function measurements to yield patient-specific flow distributions and model parameters. Using this proof-of-concept study on a cohort of six patients, we reveal substantial differences in flow distributions and clinical diagnosis metrics between the proposed personalized framework and empirical methods based purely on anatomy; these errors cannot be predicted a priori. This suggests virtual treatment planning tools would benefit from increased personalization informed by emerging imaging methods.

  View details for DOI 10.1038/s44303-024-00014-6

  View details for PubMedID 38706558

  View details for PubMedCentralID PMC11062925

• Hemodynamics and Wall Mechanics of Vascular Graft Failure. Arteriosclerosis, thrombosis, and vascular biology Szafron, J. M., Heng, E. E., Boyd, J., Humphrey, J. D., Marsden, A. L. 2024

  Abstract

  Blood vessels are subjected to complex biomechanical loads, primarily from pressure-driven blood flow. Abnormal loading associated with vascular grafts, arising from altered hemodynamics or wall mechanics, can cause acute and progressive vascular failure and end-organ dysfunction. Perturbations to mechanobiological stimuli experienced by vascular cells contribute to remodeling of the vascular wall via activation of mechanosensitive signaling pathways and subsequent changes in gene expression and associated turnover of cells and extracellular matrix. In this review, we outline experimental and computational tools used to quantify metrics of biomechanical loading in vascular grafts and highlight those that show potential in predicting graft failure for diverse disease contexts. We include metrics derived from both fluid and solid mechanics that drive feedback loops between mechanobiological processes and changes in the biomechanical state that govern the natural history of vascular grafts. As illustrative examples, we consider application-specific coronary artery bypass grafts, peripheral vascular grafts, and tissue-engineered vascular grafts for congenital heart surgery as each of these involves unique circulatory environments, loading magnitudes, and graft materials.

  View details for DOI 10.1161/ATVBAHA.123.318239

  View details for PubMedID 38572650

• Almanac - Retrieval-Augmented Language Models for Clinical Medicine. NEJM AI Zakka, C., Shad, R., Chaurasia, A., Dalal, A. R., Kim, J. L., Moor, M., Fong, R., Phillips, C., Alexander, K., Ashley, E., Boyd, J., Boyd, K., Hirsch, K., Langlotz, C., Lee, R., Melia, J., Nelson, J., Sallam, K., Tullis, S., Vogelsong, M. A., Cunningham, J. P., Hiesinger, W. 2024; 1 (2)

  Abstract

  Large language models (LLMs) have recently shown impressive zero-shot capabilities, whereby they can use auxiliary data, without the availability of task-specific training examples, to complete a variety of natural language tasks, such as summarization, dialogue generation, and question answering. However, despite many promising applications of LLMs in clinical medicine, adoption of these models has been limited by their tendency to generate incorrect and sometimes even harmful statements.We tasked a panel of eight board-certified clinicians and two health care practitioners with evaluating Almanac, an LLM framework augmented with retrieval capabilities from curated medical resources for medical guideline and treatment recommendations. The panel compared responses from Almanac and standard LLMs (ChatGPT-4, Bing, and Bard) versus a novel data set of 314 clinical questions spanning nine medical specialties.Almanac showed a significant improvement in performance compared with the standard LLMs across axes of factuality, completeness, user preference, and adversarial safety.Our results show the potential for LLMs with access to domain-specific corpora to be effective in clinical decision-making. The findings also underscore the importance of carefully testing LLMs before deployment to mitigate their shortcomings. (Funded by the National Institutes of Health, National Heart, Lung, and Blood Institute.).

  View details for DOI 10.1056/aioa2300068

  View details for PubMedID 38343631

  View details for PubMedCentralID PMC10857783

• Results following implementation of a cardiac surgery ERAS protocol. PloS one Obafemi, T., Mullis, D., Bajaj, S., Krishna, P., Boyd, J. 2023; 18 (7): e0277868

  Abstract

  Adequate peri-operative care is essential to ensuring a satisfactory outcome in cardiac surgery. In this study, we look at the impact of evidence-based protocols implemented at Stanford Hospital.This study is a single-center, retrospective analysis. Enhanced recovery after surgery (ERAS) protocols were implemented for CABG/Valve and open Aortic operations on 11/1/2017 and 6/1/2018, respectively. Propensity-score matched analysis was used to compare 30-day mortality and morbidity of patients from the pre- and post-implementation cohorts. Secondary endpoints included the following: total hospital length of stay (LOS), ICU LOS, time until extubation, and time until urinary catheter removal.After the implementation of the ERAS protocols for CABG/Valve operations, the median post-op LOS decreased from 7.0 days to 6.1 days (p<0.001), and median ICU LOS decreased from 69.9 hours to 54.0 (p = 0.098). There was no significant decrease in 30-day mortality (4% to 3.3%, p = 0.47). However, the incidence of post-op ventilator associated pneumonia (VAP) decreased from 5.0% to 2.1% (p = 0.003) and post-op urinary tract infections (UTIs) from 8.3% to 3.6% (p<0.001). Patients who underwent open aortic procedures experienced an improvement in 30-day mortality (7% to 3.5%, p = 0.012), decrease in median ICU LOS (91.7 hours to 69.6 hours, p<0.001), and a decrease in duration of mechanical ventilation (79.3 hours to 46.3 hours, p = 0.003). There was a decrease in post-op LOS, post-op VAP, and post-op UTI, although statistical significance was not attained.At Stanford Hospital, ERAS pathways have led to decreased morbidity and LOS while simultaneously improving mortality amongst our critically ill patient population.

  View details for DOI 10.1371/journal.pone.0277868

  View details for PubMedID 37450443

  View details for PubMedCentralID PMC10348550

• Almanac: Retrieval-Augmented Language Models for Clinical Medicine. Research square Zakka, C., Chaurasia, A., Shad, R., Dalal, A. R., Kim, J. L., Moor, M., Alexander, K., Ashley, E., Boyd, J., Boyd, K., Hirsch, K., Langlotz, C., Nelson, J., Hiesinger, W. 2023

  Abstract

  Large-language models have recently demonstrated impressive zero-shot capabilities in a variety of natural language tasks such as summarization, dialogue generation, and question-answering. Despite many promising applications in clinical medicine, adoption of these models in real-world settings has been largely limited by their tendency to generate incorrect and sometimes even toxic statements. In this study, we develop Almanac, a large language model framework augmented with retrieval capabilities for medical guideline and treatment recommendations. Performance on a novel dataset of clinical scenarios (n= 130) evaluated by a panel of 5 board-certified and resident physicians demonstrates significant increases in factuality (mean of 18% at p-value < 0.05) across all specialties, with improvements in completeness and safety. Our results demonstrate the potential for large language models to be effective tools in the clinical decision-making process, while also emphasizing the importance of careful testing and deployment to mitigate their shortcomings.

  View details for DOI 10.21203/rs.3.rs-2883198/v1

  View details for PubMedID 37205549

  View details for PubMedCentralID PMC10187428

• Successful Heart Transplantation Using a Portable Normothermic Ex-Vivo Donor Heart Preservation System for Extended Criteria Donor after Circulatory Death: A Case Series with Extended Perfusion Times Ruaengsri, C., Shudo, Y., Malki, A., Neto, D., Chen, R., Bethencourt, D., Hiesinger, W., MacArthur, J., Currie, M., Boyd, J., Guenthart, B., Lee, A., Woo, J. ELSEVIER SCIENCE INC. 2023: S467-S468

  View details for Web of Science ID 000992480601308

• A value-based approach to optimize red blood cell transfusion in patients receiving extracorporeal membrane oxygenation. Perfusion Shudo, Y., Cheng, N., He, H., Rosenberg, C., Hiesinger, W., Hadhazy, E., Shepard, J., Krishna, P., Resnik, J., Fong, R., Hill, C., Hsu, J. L., Maggio, P. M., Chang, S., Boyd, J. H., Woo, Y. J. 2022: 2676591221128138

  Abstract

  INTRODUCTION: The risk, cost, and adverse outcomes associated with packed red blood cell (RBC) transfusions in patients with cardiopulmonary failure requiring extracorporeal membrane oxygenation (ECMO) have raised concerns regarding the overutilization of RBC products. It is, therefore, necessary to establish optimal transfusion criteria and protocols for patients supported with ECMO. The goal of this study was to establish specific criteria for RBC transfusions in patients undergoing ECMO.METHODS: This was a retrospective cohort study conducted at Stanford University Hospital. Data on RBC utilization during the entire hospital stay were obtained, which included patients aged ≥18years who received ECMO support between 1 January 2017, and 30 June 2020 (n = 281). The primary outcome was in-hospital mortality.RESULTS: Hemoglobin (HGB) levels >10g/dL before transfusion did not improve in-hospital survival. Therefore, we revised the HGB threshold to ≤10g/dL to guide transfusion in patients undergoing ECMO. To validate this intervention, we prospectively compared the pre- and post-intervention cohorts for in-hospital mortality. Post-intervention analyses found 100% compliance for all eligible records and a decrease in the requirement for RBC transfusion by 1.2 units per patient without affecting the mortality.CONCLUSIONS: As an institution-driven value-based approach to guide transfusion in patients undergoing ECMO, we lowered the threshold HGB level. Validation of this revised intervention demonstrated excellent compliance and reduced the need for RBC transfusion while maintaining the clinical outcome. Our findings can help reform value-based healthcare in this cohort while maintaining the outcome.

  View details for DOI 10.1177/02676591221128138

  View details for PubMedID 36148806

• SARS-CoV-2 infection drives an inflammatory response in human adipose tissue through infection of adipocytes and macrophages. Science translational medicine Martínez-Colón, G. J., Ratnasiri, K., Chen, H., Jiang, S., Zanley, E., Rustagi, A., Verma, R., Chen, H., Andrews, J. R., Mertz, K. D., Tzankov, A., Azagury, D., Boyd, J., Nolan, G. P., Schürch, C. M., Matter, M. S., Blish, C. A., McLaughlin, T. L. 2022: eabm9151

  Abstract

  Obesity, characterized by chronic low-grade inflammation of the adipose tissue, is associated with adverse coronavirus disease 2019 (COVID-19) outcomes, yet the underlying mechanism is unknown. To explore whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of adipose tissue contributes to pathogenesis, we evaluated COVID-19 autopsy cases and deeply profiled the response of adipose tissue to SARS-CoV-2 infection in vitro. In COVID-19 autopsy cases, we identified SARS-CoV-2 RNA in adipocytes with an associated inflammatory infiltrate. We identified two distinct cellular targets of infection: adipocytes and a subset of inflammatory adipose tissue-resident macrophages. Mature adipocytes were permissive to SARS-CoV-2 infection; although macrophages were abortively infected, SARS-CoV-2 initiated inflammatory responses within both the infected macrophages and bystander preadipocytes. These data suggest that SARS-CoV-2 infection of adipose tissue could contribute to COVID-19 severity through replication of virus within adipocytes and through induction of local and systemic inflammation driven by infection of adipose tissue-resident macrophages.

  View details for DOI 10.1126/scitranslmed.abm9151

  View details for PubMedID 36137009

• Biodegradable external wrapping promotes favorable adaptation in an ovine vein graft model. Acta biomaterialia Ramachandra, A. B., Wang, H., Wnorowski, A., Schwarz, E. L., Pickering, J., Heiler, J. C., Lucian, H. J., Hironaka, C. E., Tran, N. A., Liu, Y., Khan, M. O., Obafemi, O., Tada, Y., Kahn, A. M., Sayed, N., Wu, J. C., Humphrey, J. D., Boyd, J., Marsden, A. L. 2022

  Abstract

  Vein grafts, the most commonly used conduits in multi-vessel coronary artery bypass grafting surgery, have high intermediate- and long-term failure rates. The abrupt and marked increase in hemodynamic loads on the vein graft is a known contributor to failure. Recent computational modeling suggests that veins can more successfully adapt to an increase in mechanical load if the rate of loading is gradual. Applying an external wrap or support at the time of surgery is one way to reduce the transmural load, and this approach has improved performance relative to an unsupported vein graft in several animal studies. Yet, a clinical trial in humans has shown benefits and drawbacks, and mechanisms by which an external wrap affects vein graft adaptation remain unknown. This study aims to elucidate such mechanisms using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, hemodynamics using computational fluid dynamics, structure using histology, and transcriptional changes using bulk RNA-sequencing in an ovine carotid-jugular interposition vein graft model, without and with an external biodegradable wrap that allows loads to increase gradually. We show that a biodegradable external wrap promotes luminal uniformity, physiological wall shear stress, and a consistent vein graft phenotype, namely, it prevents over-distension, over-thickening, intimal hyperplasia, and inflammation, and it preserves mechanotransduction. These mechanobiological insights into vein graft adaptation in the presence of an external support can inform computational growth and remodeling models of external support and facilitate design and manufacturing of next-generation external wrapping devices. STATEMENT OF SIGNIFICANCE: External mechanical support is emerging as a promising technology to prevent vein graft failure following coronary bypass graft surgery. While variants of this technology are currently under investigation in clinical trials, the fundamental mechanisms of adaptation remain poorly understood. We employ an ovine carotid-jugular interposition vein graft model, with and without an external biodegradable wrap to provide mechanical support, and probe vein graft adaptation using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, fluid flow using computational fluid dynamics, vascular composition and structure using histology, and transcriptional changes using bulk RNA sequencing. We show that the wrap mitigates vein graft failure by promoting multiple adaptive mechanisms (across biological scales).

  View details for DOI 10.1016/j.actbio.2022.08.029

  View details for PubMedID 35995404

• Impact of PhD Degree Versus Non-PhD Research Fellowship on Future Research Productivity Among Academic Cardiothoracic Surgeons. World journal of surgery Bajaj, S. S., Wang, H., Williams, K. M., Heiler, J. C., Pickering, J. M., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2022

  Abstract

  BACKGROUND: A PhD degree can offer significant research experience, but previous studies yielded conflicting conclusions on the relationship between a PhD degree and future research output. We compared the impact of a PhD degree versus research fellowship(RF) training on research productivity in cardiothoracic surgeons, hypothesizing that training pathways may influence potential associations.METHODS: CT surgeons practicing at all accredited United States CT surgery training programs in 2018 who pursued dedicated time for research (n=597), including earning a PhD degree (n=92) or completing a non-PhD RF (n=505), were included. To control for training pathways, we performed subanalyses of U.S. medical school graduates (n=466) and international medical school graduates (IMGs) (n=131). Surgeon-specific data were obtained from publicly available sources (e.g., institutional webpages, Scopus).RESULTS: PhD surgeons published greater total papers (68.5 vs. 52.0, p=0.0179) and total papers per year as an attending (4.6 vs. 3.0, p=0.0150). For U.S. medical school graduates, there were 40 PhD surgeons and 426 non-PhD RF surgeons; both groups published a similar number of total papers (64.5 vs. 54.0, p=0.3738) and total papers per year (3.2 vs. 3.0, p=0.7909). For IMGs, there were 52 PhD surgeons and 79 non-PhD RF surgeons; the PhD surgeons published greater total papers (80.5 vs. 45.0, p=0.0101) and total papers per year (5.7 vs. 2.7, p=0.0037).CONCLUSION: CT surgeons with dedicated research training are highly academically productive. Although a PhD degree may be associated with enhanced career-long research productivity for IMGs, this association was not observed for U.S. medical school graduates.

  View details for DOI 10.1007/s00268-022-06661-3

  View details for PubMedID 35871657

• Diminishing Basic Science Research Experience Among United States Cardiothoracic Surgery Trainees. The Journal of surgical research Wang, H., Bajaj, S. S., Manjunatha, K., Yu, M. M., Obafemi, O. O., Williams, K. M., Boyd, J. H. 2022; 279: 312-322

  Abstract

  INTRODUCTION: There is growing concern regarding the attrition of surgeon-scientists. To understand the decline of basic science research (BSR), it is essential to examine trends in research conducted by trainees. We hypothesized that, over recent decades, cardiothoracic (CT) surgery trainees have published fewer BSR articles.MATERIALS AND METHODS: CT surgeons at United States training institutions in 2020 who completed training in the past threedecades, excluding international trainees, were analyzed (1991-2000: n=148; 2001-2010: n=228; 2011-2020: n=247). Publication records were obtained from Scopus. Articles with medical subject heading terms involving molecular/cellular or animal research were classified as BSR using the National Institutes of Health iCite Translation module. Data were analyzed using Fisher's exact test or the Wilcoxon rank-sum test.RESULTS: While the proportion of surgeons who published a first-author paper during training remained stable over the past twodecades (178/228 [78.1%] versus 189/247 [76.5%], P=0.7427), the proportion who published a first-author BSR paper decreased significantly (135/228 [59.2%] versus 96/247 [38.9%], P<0.0001). Among surgeons who published a first-author paper in training, the total papers published by each trainee did not change over the past twodecades (3.5 versus 3.3 first-author papers per 10y of training, P=0.8819). However, the number of BSR papers published during training decreased significantly (1.7 versus 0.8 first-author papers per 10y of training, P<0.0001).CONCLUSIONS: CT surgery trainees are publishing fewer BSR papers. Additional efforts are needed to increase exposure of trainees to BSR and reaffirm that BSR is a valuable and worthwhile pursuit for academic surgeons.

  View details for DOI 10.1016/j.jss.2022.06.020

  View details for PubMedID 35809356

• An automated line-clearing chest tube system after cardiac surgery. JTCVS open Obafemi, O. O., Wang, H., Bajaj, S. S., O'Donnell, C. T., Elde, S., Boyd, J. H. 2022; 10: 246-253

  Abstract

  To complete the first in-human study of the automated line clearance Thoraguard chest tube system. The study focuses on the viability and efficacy of the device in comparison with conventional models as well as secondary matters such as patient experience and ease of use.This was a single-center, prospective, open-label study involving adult patients (n = 27) who underwent nonemergent, first-time, cardiac surgery. Patients received automated clearance chest tubes for surgical drainage in both the mediastinal and pleural spaces. The control group was retrospective (n = 80); individuals received conventional chest tubes placed and secured in locations determined at the surgeon's discretion.The automated-clearance tubes exhibited a similar drainage profile at 1, 3, 6, 12, and 24 hours compared with the conventional chest tubes. The final output at the time of tube removal was also similar (1150 [750-1590] vs 1289 [766.3-1890] mL, respectively, P = .76). The number of patients readmitted for drainage of an effusion was similar in both groups (1/27 [3.7%] vs 3/80 [3.75%], P > .99).This study has shown that the Centese Thoraguard chest tube system is a viable option for surgical chest drainage and effective when used in routine cardiac surgery operations.

  View details for DOI 10.1016/j.xjon.2022.02.020

  View details for PubMedID 36004272

  View details for PubMedCentralID PMC9390781

• Career Progression and Research Productivity of Women in Academic Cardiothoracic Surgery. The Annals of thoracic surgery Williams, K. M., Wang, H., Bajaj, S. S., Hironaka, C. E., Kasinpila, P., O'Donnell, C. T., Sanchez, M., Watkins, A. C., Lui, N. S., Backhus, L. M., Boyd, J. 2022

  Abstract

  The objective of this work was to delineate career progression and research productivity of women practicing cardiothoracic surgery in the academic setting.Cardiothoracic surgeons at the 79 accredited U.S. cardiothoracic surgery training programs in 2020 were included in this cross-sectional analysis. Data regarding sub-specialization, training, practice history, and publications were gathered from public sources including department websites, CTSNet, and Scopus.A total of 1065 surgeons (51.3% cardiac, 32.1% thoracic, 16.6% congenital) were identified. Women accounted for 10.6% (113) of the population (7.9% of cardiac, 15.5% of thoracic, 9.6% of congenital surgeons). The median number of cardiothoracic surgeons per institution was 12 [IQR 10-17], with a median of one woman [IQR 0-2]. Fifteen of 79 (19%) programs had zero women. Among women faculty, 5.3% were clinical instructors, 51.3% were assistant professors, 23.0% were associate professors, 16.8% were full professors, and 3.5% had unspecified titles (vs. 2.0%, 32.9%, 23.0%, 37.5%, and 4.6% among men, respectively, p<0.001). Women and men authored a comparable number of first-author (0.4 [0.0-1.3] vs. 0.5 [0.0-1.1], p=0.56) publications per year, but fewer last-author (0.1 [0.0-0.7] vs. 0.4 [0.0-1.3], p<0.0001) and total publications per year (2.7 [1.0-6.2] vs. 3.7 [1.3-7.8], p=0.05) than men. H-index was lower for women than for men overall (8.0 [3.0-15.0] vs. 15.0 [7.0-28.0], p<0.001), but was similar between men and women who had been practicing for 10-20 years.Gender disparities persist in academic cardiothoracic surgery. Efforts should be made to support women in achieving senior roles and academic productivity.

  View details for DOI 10.1016/j.athoracsur.2022.04.057

  View details for PubMedID 35643331

• Integration of Reinforcement Learning in a Virtual Robotic Surgical Simulation. Surgical innovation Bourdillon, A. T., Garg, A., Wang, H., Woo, Y. J., Pavone, M., Boyd, J. 2022: 15533506221095298

  Abstract

  Background. The revolutions in AI hold tremendous capacity to augment human achievements in surgery, but robust integration of deep learning algorithms with high-fidelity surgical simulation remains a challenge. We present a novel application of reinforcement learning (RL) for automating surgical maneuvers in a graphical simulation.Methods. In the Unity3D game engine, the Machine Learning-Agents package was integrated with the NVIDIA FleX particle simulator for developing autonomously behaving RL-trained scissors. Proximal Policy Optimization (PPO) was used to reward movements and desired behavior such as movement along desired trajectory and optimized cutting maneuvers along the deformable tissue-like object. Constant and proportional reward functions were tested, and TensorFlow analytics was used to informed hyperparameter tuning and evaluate performance.Results. RL-trained scissors reliably manipulated the rendered tissue that was simulated with soft-tissue properties. A desirable trajectory of the autonomously behaving scissors was achieved along 1 axis. Proportional rewards performed better compared to constant rewards. Cumulative reward and PPO metrics did not consistently improve across RL-trained scissors in the setting for movement across 2 axes (horizontal and depth).Conclusion. Game engines hold promising potential for the design and implementation of RL-based solutions to simulated surgical subtasks. Task completion was sufficiently achieved in one-dimensional movement in simulations with and without tissue-rendering. Further work is needed to optimize network architecture and parameter tuning for increasing complexity.

  View details for DOI 10.1177/15533506221095298

  View details for PubMedID 35503302

• Human Coronary Plaque T Cells Are Clonal and Cross-React to Virus and Self. Circulation research Roy Chowdhury, R., D'Addabbo, J., Huang, X., Veizades, S., Sasagawa, K., Louis, D. M., Cheng, P., Sokol, J., Jensen, A., Tso, A., Shankar, V., Wendel, B. S., Bakerman, I., Liang, G., Koyano, T., Fong, R., Nau, A., Ahmad, H., Gopakumar, J. K., Wirka, R., Lee, A., Boyd, J., Woo, Y. J., Quertermous, T., Gulati, G., Jaiswal, S., Chien, Y. H., Chan, C., Davis, M. M., Nguyen, P. K. 2022: 101161CIRCRESAHA121320090

  Abstract

  Once considered primarily a disorder of lipid deposition, coronary artery disease is an incurable, life-threatening disease that is now also characterized by chronic inflammation notable for the buildup of atherosclerotic plaques containing immune cells in various states of activation and differentiation. Understanding how these immune cells contribute to disease progression may lead to the development of novel therapeutic strategies.We used single-cell technology and in vitro assays to interrogate the immune microenvironment of human coronary atherosclerotic plaque at different stages of maturity.In addition to macrophages, we found a high proportion of αβ T cells in the coronary plaques. Most of these T cells lack high expression of CCR7 and L-selectin, indicating that they are primarily antigen-experienced, memory cells. Notably, nearly one-third of these cells express the HLA-DRA surface marker, signifying activation through their TCRs (T-cell receptors). Consistent with this, TCR repertoire analysis confirmed the presence of activated αβ T cells (CD4

  View details for DOI 10.1161/CIRCRESAHA.121.320090

  View details for PubMedID 35430876

• Analyzing the Scholarly Impact of Cardiothoracic Surgery Research Using the Relative Citation Ratio. The Journal of surgical research Wang, H., Bajaj, S. S., Williams, K. M., O'Donnell, C. T., Heiler, J. C., Krishnan, A., Pickering, J. M., Sanchez, M., Manjunatha, K., Kumar, S. S., Yu, M. M., Boyd, J. H. 2022; 275: 265-272

  Abstract

  INTRODUCTION: The National Institutes of Health (NIH) recently developed the relative citation ratio (RCR), calculated as article citations benchmarked to NIH-funded publications in the same field. Here, we characterized the scholarly impact of academic cardiothoracic (CT) surgeons and their research using the RCR.MATERIALS AND METHODS: Using a database of 992 CT surgeons, we calculated the RCR for all articles published by each surgeon since 1980 using the NIH iCite database. All data were collected from publicly available online sources. Data are presented as median (interquartile range) or as odds ratios (ORs) for multivariable logistic regression analysis.RESULTS: Where RCR 1.00 indicates equal impact as an NIH-funded publication, the RCR among all 37,402 CT surgery articles was 0.84 (0.33-1.83) and the RCR among NIH-funded CT surgery articles was 1.07 (0.53-2.17). CT surgeons exhibited a career median RCR of 0.82 (0.54-1.13) and maximum RCR of 6.20 (3.04-13.57). Predictors of career median RCR >1.00 included female gender (OR 2.23, P=0.001), thoracic subspecialization (OR 2.50, P<0.001), full professor rank (OR 1.89, P=0.001), and NIH funding (OR 1.75, P=0.001). Predictors of career maximum RCR >50th percentile among CT surgeons included male gender (OR 1.87, P=0.030), thoracic subspecialization (OR 2.05, P<0.001), full professor rank (OR 4.89, P<0.001), NIH funding (OR 3.17, P<0.001), and career duration (OR 1.03, P=0.002).CONCLUSIONS: We present the first assessment of the NIH-validated RCR for academic CT surgery. CT surgery research is highly impactful, although gender disparities persist with respect to the highest-impact research of our specialty.

  View details for DOI 10.1016/j.jss.2022.02.007

  View details for PubMedID 35306262

• Colocalization of Coronary Plaque with Wall Shear Stress in Myocardial Bridge Patients. Cardiovascular engineering and technology Khan, M. O., Nishi, T., Imura, S., Seo, J., Wang, H., Honda, Y., Nieman, K., Rogers, I. S., Tremmel, J. A., Boyd, J., Schnittger, I., Marsden, A. 2022

  Abstract

  PURPOSE: Patients with myocardial bridges (MBs) have a higher prevalence of atherosclerosis. Wall shear stress (WSS) has previously been correlated with plaque in coronary artery disease patients, but such correlations have not been investigated in symptomatic MB patients. The aim of this paper was to use a multi-scale computational fluid dynamics (CFD) framework to simulate hemodynamics in MB patient, and investigate the co-localization of WSS and plaque.METHODS: We identified N = 10 patients from a previously reported cohort of 50 symptomatic MB patients, all of whom had plaque in the proximal vessel. Dynamic 3D models were reconstructed from coronary computed tomography angiography (CCTA), intravascular ultrasound (IVUS) and catheter angiograms. CFD simulations were performed to compute WSS proximal to, within and distal to the MB. Plaque was quantified from IVUS images in 2 mm segments and registered to CFD model. Plaque area was compared to absolute and patient-normalized WSS.RESULTS: WSS was lower in the proximal segment compared to the bridge segment (6.1 ± 2.9 vs. 16.0 ± 7.1 dynes/cm2, p value < 0.01). Plaque area and plaque burden measured from IVUS peaked at 1-3 cm proximal to the MB entrance, coinciding with the first diagonal branch. Normalized WSS showed a statistically significant moderate correlation with plaque area (r = 0.41, p < 0.01).CONCLUSION: WSS may be obtained non-invasively in MB patients and provides a surrogate marker of plaque area. Using CFD, it may be possible to non-invasively assess the extent of plaque area, and identify patients who could benefit from frequent monitoring or medical management.

  View details for DOI 10.1007/s13239-022-00616-4

  View details for PubMedID 35296987

• Quantitative goals for research output and scholarly impact to enhance basic science R01 grant renewal for cardiothoracic surgeons. JTCVS open Wang, H., Bajaj, S. S., Heiler, J. C., Krishnan, A., Williams, K. M., Woo, Y. J., Boyd, J. H. 2022; 9: 162-175

  Abstract

  Objectives: Cardiothoracic (CT) surgeons with National Institutes of Health (NIH) R01 funding face a highly competitive renewal process. The factors that contribute to successful grant renewal for CT surgeons remain poorly defined. We hypothesized that renewed basic science grants are associated with high research output and scholarly impact during the preceding award cycle.Methods: Using a database of academic CT surgeons (n=992) at accredited training institutions in 2018, we identified basic science R01 grants awarded to CT surgeon principal investigators since 1985. Data for each award were obtained from publicly available online sources. Scholarly impact was evaluated using the NIH-validated relative citation ratio (RCR), defined as an article's citation rate divided by that of R01-funded publications in the same field. Continuous data are presented as medians and analyzed using the Mann-Whitney test.Results: We identified 102 basic science R01 award cycles, including 33 that were renewed (32.4%). Renewed and nonrenewed awards had a similar start year and funding period. Principal investigators of renewed versus nonrenewed awards were similar in surgical subspecialty, research training, attending experience, academic rank, and previous NIH funding. Renewed awards produced more publications per year over the funding cycle (3.4 vs 1.5; P=.0010) and exhibited a greater median RCR during the funding cycle (0.84 vs 0.66; P=.0183).Conclusions: CT surgery basic science R01 grants are associated with high research output and scholarly impact. At the 50th percentile among renewed grants, CT surgeons published 3.4 funded manuscripts per year with a median RCR of 0.84 during the previous award cycle.

  View details for DOI 10.1016/j.xjon.2021.10.063

  View details for PubMedID 36003453

• Post-Transplant Extracorporeal Membrane Oxygenation for Severe Primary Graft Dysfunction to Support the Use of Marginal Donor Hearts. Transplant international : official journal of the European Society for Organ Transplantation Shudo, Y., Alassar, A., Wang, H., Lingala, B., He, H., Zhu, Y., Hiesinger, W., MacArthur, J. W., Boyd, J. H., Lee, A. M., Currie, M., Woo, Y. J. 2022; 35: 10176

  Abstract

  Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7days following OHT (range: 1-12days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.

  View details for DOI 10.3389/ti.2022.10176

  View details for PubMedID 35340846

• Relationship Between Coronary Atheroma, Epicardial Adipose Tissue Inflammation, and Adipocyte Differentiation Across the Human Myocardial Bridge. Journal of the American Heart Association McLaughlin, T., Schnittger, I., Nagy, A., Zanley, E., Xu, Y., Song, Y., Nieman, K., Tremmel, J. A., Dey, D., Boyd, J., Sacks, H. 2021: e021003

  Abstract

  Background Inflammation in epicardial adipose tissue (EAT) may contribute to coronary atherosclerosis. Myocardial bridge is a congenital anomaly in which the left anterior descending coronary artery takes a "tunneled" course under a bridge of myocardium: while atherosclerosis develops in the proximal left anterior descending coronary artery, the bridged portion is spared, highlighting the possibility that geographic separation from inflamed EAT is protective. We tested the hypothesis that inflammation in EAT was related to atherosclerosis by comparing EAT from proximal and bridge depots in individuals with myocardial bridge and varying degrees of atherosclerotic plaque. Methods and Results Maximal plaque burden was quantified by intravascular ultrasound, and inflammation was quantified by pericoronary EAT signal attenuation (pericoronary adipose tissue attenuation) from cardiac computed tomography scans. EAT overlying the proximal left anterior descending coronary artery and myocardial bridge was harvested for measurement of mRNA and microRNA (miRNA) using custom chips by Nanostring; inflammatory cytokines were measured in tissue culture supernatants. Pericoronary adipose tissue attenuation was increased, indicating inflammation, in proximal versus bridge EAT, in proportion to atherosclerotic plaque. Individuals with moderate-high versus low plaque burden exhibited greater expression of inflammation and hypoxia genes, and lower expression of adipogenesis genes. Comparison of gene expression in proximal versus bridge depots revealed differences only in participants with moderate-high plaque: inflammation was higher in proximal and adipogenesis lower in bridge EAT. Secreted inflammatory cytokines tended to be higher in proximal EAT. Hypoxia-inducible factor 1a was highly associated with inflammatory gene expression. Seven miRNAs were differentially expressed by depot: 3192-5P, 518D-3P, and 532-5P were upregulated in proximal EAT, whereas miR 630, 575, 16-5P, and 320E were upregulated in bridge EAT. miR 630 correlated directly with plaque burden and inversely with adipogenesis genes. miR 3192-5P, 518D-3P, and 532-5P correlated inversely with hypoxia/oxidative stress, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PCG1a), adipogenesis, and angiogenesis genes. Conclusions Inflammation is specifically elevated in EAT overlying atherosclerotic plaque, suggesting that EAT inflammation is caused by atherogenic molecular signals, including hypoxia-inducible factor 1a and/or miRNAs in an "inside-to-out" relationship. Adipogenesis was suppressed in the bridge EAT, but only in the presence of atherosclerotic plaque, supporting cross talk between the vasculature and EAT. miR 630 in EAT, expressed differentially according to burden of atherosclerotic plaque, and 3 other miRNAs appear to inhibit key genes related to adipogenesis, angiogenesis, hypoxia/oxidative stress, and thermogenesis in EAT, highlighting a role for miRNA in mediating cross talk between the coronary vasculature and EAT.

  View details for DOI 10.1161/JAHA.121.021003

  View details for PubMedID 34726081

• The Academic Impact of Advanced Clinical Fellowship Training among General Thoracic Surgeons. Journal of surgical education Patel, D. C., Wang, H., Bajaj, S. S., Williams, K. M., Pickering, J. M., Heiler, J. C., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H., Backhus, L. M. 2021

  Abstract

  OBJECTIVE: Advanced clinical fellowship training has become a popular option for surgical trainees seeking to bolster their clinical training and expertise. However, the long-term academic impact of this additional training following a traditional thoracic surgery fellowship is unknown. This study aimed to delineate the impact of an advanced clinical fellowship on subsequent research productivity and advancement in academic career among general thoracic surgeons.METHODS: Using an internally constructed database of active, academic general thoracic surgeons who are current faculty at accredited cardiothoracic surgery training programs within the United States, surgeons were dichotomized according to whether an advanced clinical fellowship was completed or not. Academic career metrics measured by research productivity, scholarly impact (H-index), funding by the National Institutes of Health, and academic rank were compared.RESULTS: Among 285 general thoracic surgeons, 89 (31.2%) underwent an advanced fellowship, whereas 196 (68.8%) did not complete an advanced fellowship. The most commonly pursued advanced fellowship was minimally invasive thoracic surgery (32.0%). There were no differences between the two groups in terms of gender, international medical training, or postgraduate education. Those who completed an advanced clinical fellowship were less likely to have completed a dedicated research fellowship compared to those who had not completed any additional clinical training (58.4% vs. 74.0%, p = 0.0124). Surgeons completing an advanced clinical fellowship demonstrated similar cumulative first-author publications (p = 0.4572), last-author publications (p = 0.7855), H-index (p = 0.9651), National Institutes of Health funding (p = 0.7540), and years needed to advance to associate professor (p = 0.3410) or full rank professor (p = 0.1545) compared to surgeons who did not complete an advanced fellowship. These findings persisted in sub-analyses controlling for surgeons completing a dedicated research fellowship.CONCLUSIONS: Academic general thoracic surgeons completing an advanced clinical fellowship demonstrate similar research output and ascend the academic ladder at a similar pace as those not pursuing additional training.

  View details for DOI 10.1016/j.jsurg.2021.09.003

  View details for PubMedID 34674980

• Impact of Diastolic Vessel Restriction on Quality of Life in Symptomatic Myocardial Bridging Patients Treated With Surgical Unroofing: Preoperative Assessments With Intravascular Ultrasound and Coronary Computed Tomography Angiography. Circulation. Cardiovascular interventions Hashikata, T., Honda, Y., Wang, H., Pargaonkar, V. S., Nishi, T., Hollak, M. B., Rogers, I. S., Nieman, K., Yock, P. G., Fitzgerald, P. J., Schnittger, I., Boyd, J. H., Tremmel, J. A. 2021; 14 (10): e011062

  Abstract

  [Figure: see text].

  View details for DOI 10.1161/CIRCINTERVENTIONS.121.011062

  View details for PubMedID 34665656

• Characterization of academic cardiothoracic surgeons who started as attendings in private or community practice. Surgery Bajaj, S. S., Wang, H., Williams, K. M., Krishnan, A., Heiler, J. C., Pickering, J. M., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2021

  Abstract

  BACKGROUND: Surgeons are traditionally categorized as working either in academic or private/community practice, but some transition between the two environments. Here, we profile current academic cardiothoracic surgeons who began their attending careers in private or community practice. We hypothesized that research activity may distinguish cardiothoracic surgeons who started in non-academic versus academic practice.METHODS: Publicly available data regarding professional history and research productivity were collected for 992 academic cardiothoracic surgeons on faculty at the 77 cardiothoracic surgery training programs in the United States in 2018. Data are presented as medians analyzed with the Mann-Whitney test or proportions analyzed with Fisher exact test or the chi2 test.RESULTS: A total of 80 (8.1%) academic cardiothoracic surgery faculty started their careers in non-academic practice, and 912 (91.9%) started directly in academia. Those who started in non-academic practice spent a median 7.0 y in private/community practice and were more likely to be cardiac surgeons (68.8% vs 51.6%, P= .0132). They were equally likely to pursue a protected research fellowship (56.3% vs 57.0%, P= .9067) and publish research during training (92.5% vs 91.1%, P= .8374), but they published fewer total papers by the end of cardiothoracic surgery fellowship (3.0 vs 7.0, P= .0001) and fewer papers per year as an academic attending (0.8 vs 2.9, P < .0001). Nevertheless, the majority of cardiothoracic surgery faculty who started in non-academic practice are currently active in research (68.8%), and 2 such surgeons received National Institutes of Health R01 funding.CONCLUSION: Transitioning from non-academic to academic practice is an uncommon but feasible pathway for interested cardiothoracic surgeons.

  View details for DOI 10.1016/j.surg.2021.06.012

  View details for PubMedID 34294448

• IMPACT OF DIASTOLIC VESSEL RESTRICTION ON CLINICAL SYMPTOMS IN PATIENTS WITH SYMPTOMATIC MYOCARDIAL BRIDGING Hashikata, T., Honda, Y., Wang, H., Pargaonkar, V., Hollak, M., Rogers, I. S., Yock, P., Fitzgerald, P., Schnittger, I., Boyd, J., Tremmel, J. ELSEVIER SCIENCE INC. 2021: 165

  View details for Web of Science ID 000647487500165

• INTRAOPERATIVE INDUCIBILITY OF ATRIAL FIBRILLATION IMPROVES RISK STRATIFICATION AND REDUCES POST-OPERATIVE ATRIAL FIBRILLATION Pong, T., Cyr, K., Carlton, C., Niesen, J., Aparicio-Valenzuela, J., Fischbein, M., Woo, Y., Boyd, J., Lee, A. ELSEVIER SCIENCE INC. 2021: 1592

  View details for Web of Science ID 000647487501599

• The Use of Factor Eight Inhibitor Bypass Activity (FEIBA) for the Treatment of Perioperative Hemorrhage in Left Ventricular Assist Device Implantation. Journal of cardiothoracic and vascular anesthesia O'Donnell, C., Rodriguez, A. J., Madhok, J., Sharifi, H., Wang, H., O'Brien, C. G., Boyd, J., Hiesinger, W., Hsu, J., Hill, C. C. 2021

  Abstract

  OBJECTIVE: To test the hypothesis that factor eight inhibitor bypassing activity (FEIBA) can be used to control bleeding following left ventricular assist device (LVAD) implantation without increasing the 14-day composite thrombotic outcome of pump thrombus, ischemic cerebrovascular accidents, pulmonary embolism, and deep venous thrombosis.DESIGN: Retrospective cohort study.SETTING: Academic hospital.PARTICIPANTS: Three hundred nineteen consecutive patients who underwent LVAD implantation (December 1, 2009 to December 30, 2018).INTERVENTION: FEIBA administered to control perioperative hemorrhage.MEASUREMENTS AND MAIN RESULTS: The 82 patients (25.7%) in the FEIBA cohort had more risk factors for perioperative hemorrhage, such as lower preoperative platelet count (169 ± 66 v 194 ± 68 * 103/mL, p = 0.004), prior cardiac surgery (36.6% v 21.9%, p = 0.008), and longer cardiopulmonary bypass (CPB) time (100.3 v 75.2 minutes, p = 0.001) than the 237 controls. After 16.6 units (95% CI: 14.3-18.9) of blood products were given, 992 units (95% CI: 821-1163) of FEIBA were required to control bleeding in the FEIBA cohort. Compared to the controls, there were no differences in the 14-day composite thrombotic outcome (11.0% v 7.6%, p = 0.343) or mortality rate (3.7% v 1.3%, p = 0.179). Multivariate logistical regression identified preoperative international normalized ratio (odds ratio [OR]: 1.30, 95% CI: 1.04-1.62) and CPB time (OR: 1.11, 95% CI: 1.02-1.20) as risk factors for 14-day thrombotic events, but FEIBA usage was not associated with an increased risk.CONCLUSIONS: In this retrospective cohort study, the use of FEIBA (1,000 units, 13 units/kg) to control perioperative hemorrhage following LVAD implantation was not associated with increases in mortality or composite thrombotic outcome.

  View details for DOI 10.1053/j.jvca.2021.04.030

  View details for PubMedID 34034934

• Career Research Productivity Correlates With Medical School Ranking Among Cardiothoracic Surgeons. The Journal of surgical research Bajaj, S. S., Wang, H., Williams, K. M., Pickering, J. M., Heiler, J. C., Manjunatha, K., Sanchez, M., O'Donnell, C. T., Boyd, J. H. 2021; 264: 99–106

  Abstract

  BACKGROUND: The foundation for a successful academic surgical career begins in medical school. We examined whether attending a top-ranked medical school is correlated with enhanced research productivity and faster career advancement among academic cardiothoracic (CT) surgeons.MATERIALS AND METHODS: Research profiles and professional histories were obtained from publicly available sources for all CT surgery faculty at accredited US CT surgery teaching hospitals in 2018 (n=992). We focused on surgeons who completed medical school in the United States during or after 1990, the first-year US News & World Report released its annual medical school research rankings (n=451). Subanalyses focused on surgeons who completed a research fellowship (n=299) and those who did not (n=152).RESULTS: A total of 124 surgeons (27.5%) attended a US News & World Report top 10 medical school, whereas 327 (72.5%) did not. Surgeons who studied at a top 10 medical school published more articles per year as an attending surgeon (3.2 versus 1.9; P<0.0001), leading to more total publications (51.5 versus 27.0; P<0.0001) and a higher H-index (16.0 versus 11.0; P<0.0001) over a similar career duration (11.0 versus 10.0y; P=0.1294). These differences in career-long research productivity were statistically significant regardless of whether the surgeons completed a research fellowship or not. The surgeons in both groups, however, required a similar number of years to reach associate professor rank (P=0.6993) and full professor rank (P=0.7811) after starting their first attending job.CONCLUSIONS: Attending a top-ranked medical school is associated with enhanced future research productivity but not with faster career advancement in academic CT surgery.

  View details for DOI 10.1016/j.jss.2021.01.008

  View details for PubMedID 33794390

• Computational evaluation of venous graft geometries in coronary artery bypass surgery. Seminars in thoracic and cardiovascular surgery Seo, J. n., Ramachandra, A. B., Boyd, J. n., Marsden, A. L., Kahn, A. M. 2021

  Abstract

  Cardiothoracic surgeons are faced with a choice of different revascularization techniques and diameters for saphenous vein grafts (SVG) in coronary artery bypass graft surgery (CABG). Using computational simulations, we virtually investigate the effect of SVG geometry on hemodynamics of both venous grafts and the target coronary arteries. We generated patient-specific three-dimensional anatomic models of CABG patients and quantified mechanical stimuli. We performed virtual surgery on three patient-specific models by modifying the geometry vein grafts to reflect single, Y, and sequential surgical configurations with SVG diameters ranging from 2 mm to 5 mm. Our study demonstrates that the coronary artery runoffs are relatively insensitive to the choice of SVG revascularization geometry. We observe a 10% increase in runoff when the SVG diameter is changed from 2 mm to 5 mm. The wall shear stress (WSS) of SVG increases dramatically when the diameter drops, following an inverse power scaling with diameter. For a fixed diameter, the average wall shear stress on the vein graft varies in ascending order as single, Y, and sequential graft in the patient cohort. The runoff to the target coronary arteries changes marginally due to the choice of graft configuration or diameter. The shear stress on the vein graft depends on both flow rate and diameter and follows an inverse power scaling consistent with a Poiseuille flow assumption. Given the similarity in runoff with different surgical configurations, choices of SVG geometries can be informed by propensity for graft failure using shear stress evaluations.

  View details for DOI 10.1053/j.semtcvs.2021.03.007

  View details for PubMedID 33711465

• Characterization of Cardiothoracic Surgeons Actively Leading Basic Science Research. The Journal of surgical research Wang, H., Bajaj, S. S., Krishnan, A., Heiler, J. C., Williams, K. M., Pickering, J. M., Manjunatha, K., Sanchez, M., O'Donnell, C. T., Boyd, J. H. 2021; 268: 371-380

  Abstract

  There is increasing concern regarding the attrition of surgeon-scientists in cardiothoracic (CT) surgery. However, the characteristics of CT surgeons who are actively leading basic science research (BSR) have not been examined. We hypothesized that early exposure to BSR during training and active grant funding are important factors that facilitate the pursuit of BSR among practicing CT surgeons.We created a database of 992 CT surgeons listed as faculty at accredited United States CT surgery teaching hospitals in 2018. Data regarding each surgeon's training/professional history, publication record, and National Institutes of Health funding were acquired from publicly available online sources. Surgeons who published at least one first- or last-author paper in 2017-2018 were considered to be active, lead researchers.Of the 992 CT surgeons, 73 (7.4%) were actively leading BSR, and 599 (60.4%) were actively leading only non-BSR. Only 2 women were actively leading BSR. Surgeons actively leading BSR were more likely to have earned a PhD degree (20.5% versus 9.7%, P = 0.0049), and more likely to have published a first-author BSR paper during training (76.7% versus 40.9%, P< 0.0001). Surgeons actively leading BSR were also more likely to have an active National Institutes of Health grant (34.2% versus 5.8%, P< 0.0001), especially an R01 grant (21.9% versus 2.5%, P< 0.0001).A small minority of CT surgeons at academic training hospitals are actively leading BSR. In order to facilitate the development of surgeon-scientists, additional support must be given to trainees and junior faculty, especially women, to enable early engagement in BSR.

  View details for DOI 10.1016/j.jss.2021.06.065

  View details for PubMedID 34399359

• THE SAFETY AND EFFICACY OF PERIOPERATIVE FEIBA AFTER LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION ODonnell, C., Rodriguez, A., Madhok, J., Wang, H., Shad, R., Sharifi, H., Boyd, J., William, H., Hsu, J., Hill, C. LIPPINCOTT WILLIAMS & WILKINS. 2021: 168

  View details for Web of Science ID 000672597100323

• National Institutes of Health R01 Grant Funding Is Associated with Enhanced Research Productivity and Career Advancement Among Academic Cardiothoracic Surgeons. Seminars in thoracic and cardiovascular surgery Bajaj, S. S., Wang, H., Williams, K. M., Pickering, J. M., Heiler, J. C., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2020

  Abstract

  National Institutes of Health (NIH) funding has declined among cardiothoracic surgeons. R01 grants are a well-known mechanism to support high-impact research, and we sought to clarify the association between NIH funding and academic achievement. We hypothesized that cardiothoracic surgeons who acquired R01 funding exhibit greater research output and faster career advancement. All cardiothoracic surgeons (n=992) working at accredited United States cardiothoracic surgery training hospitals in 2018 were included. Institutional webpages, Scopus, and Grantome were utilized to collect publicly-available data regarding each surgeon's training and career history, research publications, and NIH funding. 78 (7.9%) surgeons obtained R01 funding as a principal investigator, while 914 (92.1%) did not. R01-funded surgeons started their attending careers earlier (1998 vs 2005, p<0.0001) and were more likely to have pursued dedicated research training (p<0.0001). R01-funded surgeons authored 5.3 publications/year before their first R01 grant, 9.3 during the grant period, and 8.6 after the grant expired, all of which were greater than the publication rate of non-R01-funded surgeons at comparable career timepoints (2.0-3.0 publications/year, p<0.0001). Among time-matched surgeons who completed medical school in 1998 or earlier (n=73 R01-funded vs n=602 non-funded), R01-funded surgeons have published more total publications (178.0 vs 56.5 papers, p<0.0001) and exhibit a greater H-index (41.0 vs 19.0, p<0.0001). R01-funded surgeons have also advanced to higher academic ranks (p<0.0001) and are more likely to be chiefs of their departments or divisions (42.5% vs 25.7%, p=0.0035). Cardiothoracic surgeons who obtain R01 funding exhibit greater research productivity and faster career advancement.

  View details for DOI 10.1053/j.semtcvs.2020.12.002

  View details for PubMedID 33359763

• Comparison of Postoperative Pain From Catheter Over the Needle (CON) Versus Catheter Through Needle (CTN) Techniques for Erector Spinae Plane Blockade in Patients Undergoing Open Heart Surgery: A Single-Center Retrospective Review. Journal of cardiothoracic and vascular anesthesia Pfaff, K., Brodt, J., Basireddy, S., Boyd, J., Boublik, J., Horn, J., Tsui, B. C. 2020

  View details for DOI 10.1053/j.jvca.2020.11.060

  View details for PubMedID 33342733

• Early Engagement in Cardiothoracic Surgery Research Enhances Future Academic Productivity. The Annals of thoracic surgery Wang, H., Bajaj, S. S., Williams, K. M., Heiler, J. C., Pickering, J. M., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2020

  Abstract

  BACKGROUND: Early engagement in cardiothoracic (CT) surgery research may help attract trainees to academic CT surgery, but whether this early exposure boosts career-long academic achievement remains unknown.METHODS: A database of all CT surgery faculty at accredited, academic CT surgery training programs in the United States during the year 2018 was established. Excluding international medical graduates, surgeons who started general surgery residency in the United States prior to 2004 and who published at least one manuscript prior to traditional CT fellowship training were included (n=472). Each surgeon's educational background, work history, and research publications were recorded from publicly-available online sources.RESULTS: In total, 370 surgeons (78.4%) co-authored a CT surgery manuscript before fellowship training, while 102 (21.6%) published only on subjects unrelated to CT surgery. Regardless of whether surgeons pursued dedicated research training or not, those who co-authored a CT surgery manuscript prior to fellowship training published more papers per year as an attending (p<0.01), resulting in more total publications (p<0.01) and a higher H-index (p<0.01) over comparably long careers. Among CT surgeons who did not publish CT surgery research prior to fellowship training, those who co-authored a CT surgery manuscript during fellowship also exhibited enhanced future academic productivity.CONCLUSIONS: Academic CT surgeons who published CT surgery research prior to fellowship training ultimately exhibit more prolific and impactful research profiles compared to those who published only on subjects unrelated to CT surgery during training. Efforts to increase early engagement in CT surgery research among trainees should be fully endorsed.

  View details for DOI 10.1016/j.athoracsur.2020.10.013

  View details for PubMedID 33159869

• New Attending Surgeons Hired by Their Training Institution Exhibit Greater Research Productivity. The Annals of thoracic surgery Bajaj, S. S., Wang, H., Williams, K. M., Pickering, J. M., Heiler, J. C., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2020

  Abstract

  BACKGROUND: A first attending job often sets the tone for academic surgeons' future careers, and many graduating trainees are faced with the decision to begin their career at their training institution or another institution. We hypothesized that surgeons hired as first-time faculty at their cardiothoracic surgery fellowship (CSF) institution exhibit greater research productivity and career advancement than those hired as first-time faculty at a different institution.METHODS: Cardiothoracic surgeons who were listed as clinical faculty at all 77 accredited U.S. cardiothoracic surgery training programs and who trained via the general surgery residency and CSF pathway in 2018 were included (n=904). Surgeon-specific data regarding professional history, publications, and grant funding were obtained from publicly available sources.RESULTS: 294/904 (32.5%) surgeons were hired as first-time faculty at their CSF institution while 610/904 (67.5%) surgeons were hired at a different institution (start year 2005 vs 2006, p=0.3424). Both groups exhibited similar research productivity upon starting their first job (total papers: 7.0 vs 7.0, p=0.5913). Following them to the present, surgeons hired at their CSF institution produced more total papers (64.5 vs 39.0, p<0.0001) and exhibited a higher H-index (20.0 vs 14.0, p<0.0001). Surgeons in both groups required a similar amount of time to achieve associate (p=0.2079) and full professor (p=0.5925) ranks.CONCLUSIONS: Surgeons hired as first-time faculty at their CSF institution may experience benefits to research productivity but not career advancement. Trainees may find it advantageous to begin their careers in a familiar environment where they have already formed a robust specialty-specific network.

  View details for DOI 10.1016/j.athoracsur.2020.09.026

  View details for PubMedID 33152331

• Commentary: Keep your friends close. The Journal of thoracic and cardiovascular surgery Boyd, J. H. 2020

  View details for DOI 10.1016/j.jtcvs.2020.08.089

  View details for PubMedID 33008576

• Impact of advanced clinical fellowship training on future research productivity and career advancement in adult cardiac surgery. Surgery Wang, H., Bajaj, S. S., Williams, K. M., Pickering, J. M., Heiler, J. C., Manjunatha, K., O'Donnell, C. T., Sanchez, M., Boyd, J. H. 2020

  Abstract

  BACKGROUND: Advanced clinical fellowships are important for training surgeons with a niche expertise. Whether this additional training impacts future academic achievement, however, remains unknown. Here, we investigated the impact of advanced fellowship training on research productivity and career advancement among active, academic cardiac surgeons. We hypothesized that advanced fellowships do not significantly boost future academic achievement.METHODS: Using online sources (eg, department webpages, CTSNet, Scopus, Grantome), we studied adult cardiac surgeons who are current faculty at accredited United States cardiothoracic surgery training programs, and who have practiced only at United States academic centers since 1986 (n= 227). Publicly available data regarding career advancement, research productivity, and grant funding were collected. Data are expressed as counts or medians.RESULTS: In our study, 78 (34.4%) surgeons completed an advanced clinical fellowship, and 149 (65.6%) did not. Surgeons who pursued an advanced fellowship spent more time focused on surgical training (P < .0001), and those who did not were more likely to have completed a dedicated research fellowship (P= .0482). Both groups exhibited similar cumulative total publications (P= .6862), H-index (P= .6232), frequency of National Institutes of Health grant funding (P= .8708), and time to achieve full professor rank (P= .7099). After stratification by current academic rank, or by whether surgeons pursued a dedicated research fellowship, completion of an advanced clinical fellowship was not associated with increased research productivity or accelerated career advancement.CONCLUSION: Academic adult cardiac surgeons who pursue advanced clinical fellowships exhibit similar research productivity and similar career advancement as those who do not pursue additional clinical training.

  View details for DOI 10.1016/j.surg.2020.06.016

  View details for PubMedID 32747139

• Clinical trial in a dish using iPSCs shows lovastatin improves endothelial dysfunction and cellular cross-talk in LMNA cardiomyopathy. Science translational medicine Sayed, N., Liu, C., Ameen, M., Himmati, F., Zhang, J. Z., Khanamiri, S., Moonen, J., Wnorowski, A., Cheng, L., Rhee, J., Gaddam, S., Wang, K. C., Sallam, K., Boyd, J. H., Woo, Y. J., Rabinovitch, M., Wu, J. C. 2020; 12 (554)

  Abstract

  Mutations in LMNA, the gene that encodes lamin A and C, causes LMNA-related dilated cardiomyopathy (DCM) or cardiolaminopathy. LMNA is expressed in endothelial cells (ECs); however, little is known about the EC-specific phenotype of LMNA-related DCM. Here, we studied a family affected by DCM due to a frameshift variant in LMNA Human induced pluripotent stem cell (iPSC)-derived ECs were generated from patients with LMNA-related DCM and phenotypically characterized. Patients with LMNA-related DCM exhibited clinical endothelial dysfunction, and their iPSC-ECs showed decreased functionality as seen by impaired angiogenesis and nitric oxide (NO) production. Moreover, genome-edited isogenic iPSC lines recapitulated the EC disease phenotype in which LMNA-corrected iPSC-ECs showed restoration of EC function. Simultaneous profiling of chromatin accessibility and gene expression dynamics by combining assay for transposase-accessible chromatin using sequencing (ATAC-seq) and RNA sequencing (RNA-seq) as well as loss-of-function studies identified Kruppel-like factor 2 (KLF2) as a potential transcription factor responsible for the EC dysfunction. Gain-of-function studies showed that treatment of LMNA iPSC-ECs with KLF2 agonists, including lovastatin, rescued the EC dysfunction. Patients with LMNA-related DCM treated with lovastatin showed improvements in clinical endothelial dysfunction as indicated by increased reactive hyperemia index. Furthermore, iPSC-derived cardiomyocytes (iPSC-CMs) from patients exhibiting the DCM phenotype showed improvement in CM function when cocultured with iPSC-ECs and lovastatin. These results suggest that impaired cross-talk between ECs and CMs can contribute to the pathogenesis of LMNA-related DCM, and statin may be an effective therapy for vascular dysfunction in patients with cardiolaminopathy.

  View details for DOI 10.1126/scitranslmed.aax9276

  View details for PubMedID 32727917

• Relation of Length of Survival After Orthotopic Heart Transplantation to Age of the Donor. The American journal of cardiology Shudo, Y., Guenther, S. P., Lingala, B., He, H., Hiesinger, W., MacArthur, J. W., Currie, M. E., Lee, A. M., Boyd, J. H., Woo, Y. J. 2020

  Abstract

  We aim to evaluate the impact of donor age on the outcomes in orthotropic heart transplantation recipients. The United Network for Organ Sharing database was queried for adult patients (age; ≥60) underwent first-time orthotropic heart transplantation between 1987 and 2019 (n = 18,447). We stratified the cohort by donor age; 1,702 patients (9.2%) received a heart from a donor age of <17 years; 11,307 patients (61.3%) from a donor age of 17 ≥, < 40; 3,525 patients (19.1%) from a donor age of 40 ≥, < 50); and 1,913 patients (10.4%) from a donor age of ≥50. There was a significant difference in the survival likelihood (p < 0.0001) based on donor's age-based categorized cohort, however, the median survival was 10.5 years in the cohort in whom the donor was <17, 10.3 years in whom the donor was 17 ≥, < 40, 9.4 years in whom the donor was 40 ≥, < 50, and 9.0 years in whom the donor was ≥ 50. Additionally, there was no significant difference in the episode of acute rejection (p = 0.19) nor primary graft failure (p = 0.24). In conclusion, this study demonstrated that patients receiving hearts from the donor age of ≥50 years old showed slight inferior survival likelihood, but appeared to be equivalent median survival.

  View details for DOI 10.1016/j.amjcard.2020.06.036

  View details for PubMedID 32736794

• Screening and Prophylactic Amiodarone Reduces Post-Operative Atrial Fibrillation in At-Risk Patients JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Pong, T., Cyr, K., Niesen, J., Aparicio-Valenzuela, J., Carlton, C., Fischbein, M. P., Woo, Y., Boyd, J. H., Lee, A. M. 2020; 75 (11): 1361–63

  View details for DOI 10.1016/j.jacc.2020.01.016

  View details for Web of Science ID 000520057100016

  View details for PubMedID 32192666

• Fractional Flow Reserve to Guide Coronary Artery Bypass Graft Surgery. JACC. Cardiovascular interventions Fearon, W. F., Boyd, J. H. 2020

  View details for DOI 10.1016/j.jcin.2020.01.209

  View details for PubMedID 32222437

• Endoscopic Radial Artery Harvesting During Anesthesia Line Placement Reduces the Time and Cost of Multivessel Coronary Artery Bypass Grafting. Innovations (Philadelphia, Pa.) Wang, H., Bilbao, M. S., Miller, S. L., O'Donnell, C. T., Boyd, J. H. 2020: 1556984519882014

  Abstract

  OBJECTIVE: Endoscopic radial artery (RA) harvesting performed concurrently with internal mammary artery (IMA) takedown and endoscopic saphenous vein (SV) harvesting creates a crowded and inefficient operating room environment. We assessed the effect of a presternotomy RA harvest strategy on surgery time and costs.METHODS: A total of 41 patients underwent elective, first-time, isolated multivessel on-pump coronary artery bypass grafting including an IMA, RA, and SV graft. The first 20 patients (Phase I) underwent endoscopic RA harvesting concurrently with IMA takedown and endoscopic SV harvesting after sternotomy, requiring two sets of endoscopic harvesting equipment per case, each used by a separate individual. The final 21 patients (Phase II) underwent endoscopic RA harvesting during anesthesia line placement, completing the procedure before sternotomy, thus requiring only one set of endoscopic harvesting equipment reused by a single individual.RESULTS: There were no differences in baseline patient characteristics, number of bypasses, duration of SV or RA harvest time, or duration of cardiopulmonary bypass or cross-clamp time between the two groups. Total surgery time was reduced by 32 minutes in Phase II (P = 0.044). Relative to a total hospital direct cost of 100.00 units, total surgery costs were reduced from 29.33 units in Phase I to 25.62 units in Phase II (P = 0.001). No anesthesia- or RA harvest-related complications occurred in either group.CONCLUSIONS: Endoscopic RA harvesting can be safely performed during anesthesia line placement prior to sternotomy. Our simple but innovative strategy improves intraoperative workflow, reduces the time and cost of surgery, and advances the delivery of high-quality patient care.

  View details for DOI 10.1177/1556984519882014

  View details for PubMedID 31903868

• Type A Aortic Dissection-Experience Over 5 Decades: JACC Historical Breakthroughs in Perspective. Journal of the American College of Cardiology Zhu, Y. n., Lingala, B. n., Baiocchi, M. n., Tao, J. J., Toro Arana, V. n., Khoo, J. W., Williams, K. M., Traboulsi, A. A., Hammond, H. C., Lee, A. M., Hiesinger, W. n., Boyd, J. n., Oyer, P. E., Stinson, E. B., Reitz, B. A., Mitchell, R. S., Miller, D. C., Fischbein, M. P., Woo, Y. J. 2020; 76 (14): 1703–13

  Abstract

  The Stanford classification of aortic dissection was described in 1970. The classification proposed that type A aortic dissection should be surgically repaired immediately, whereas type B aortic dissection can be treated medically. Since then, diagnostic tools and management of acute type A aortic dissection (ATAAD) have undergone substantial evolution. This paper evaluated historical changes of ATAAD repair at Stanford University since the establishment of the aortic dissection classification 50 years ago. The surgical approaches to the proximal and distal extent of the aorta, cerebral perfusion methods, and cannulation strategies were reviewed. Additional analyses using patients who underwent ATAAD repair at Stanford University from 1967 through December 2019 were performed to further illustrate the Stanford experience in the management of ATAAD. While technical complexity increased over time, post-operative survival continued to improve. Further investigation is warranted to delineate factors associated with the improved outcomes observed in this study.

  View details for DOI 10.1016/j.jacc.2020.07.061

  View details for PubMedID 33004136

• Impact of Surgical Approach in Double Lung Transplantation: Median Sternotomy vs Clamshell Thoracotomy. Transplantation proceedings Shudo, Y. n., Rinewalt, D. n., Lingala, B. n., Kim, F. Y., He, H. n., Boyd, J. H., Lee, A. M., Hiesinger, W. n., Currie, M. E., MacArthur, J. W., Woo, Y. J. 2020

  Abstract

  Double lung transplantation (DLT) remains the gold standard for end-stage lung disease. Although DLT was historically performed via clamshell thoracotomy, recently the median sternotomy has emerged as a viable alternative. As the ideal surgical approach remains unclear, the aim of our study was to compare the short- and long-term outcomes of these 2 surgical approaches in DLT.We retrospectively reviewed 192 consecutive adult patients who underwent primary DLT at our institution between 2012 and 2017 (sternotomy, n = 147; clamshell, n = 45). The impact of each surgical approach on post-transplant morbidity was investigated, and the overall survival probability analyses were performed.There were no significant differences in recipients' baseline and donors' characteristics and bilateral allograft ischemic time. Freedom from primary graft dysfunction, acute rejection episodes, postoperative prolonged ventilator support, tracheostomy, postoperative stroke, and airway dehiscence were comparable between these 2 groups. The duration of cardiopulmonary bypass and operative time were significantly longer in the clamshell thoracotomy group. Postoperative extracorporeal membrane oxygenation usage tended to be more frequent in the clamshell thoracotomy group than the median sternotomy group, despite no statistical significance. Length of hospital and intensive care unit stay were not influenced by the type of incision. There was no significant difference in overall survival between these 2 procedure groups (P = .61, log-rank test).The median sternotomy approach in DLT decreases operative time and more importantly leads to a shorter duration of cardiopulmonary bypass. The type of surgical approach did not show any statistically significant impact on adult DLT recipients' morbidity and survival.

  View details for DOI 10.1016/j.transproceed.2019.10.018

  View details for PubMedID 31911057

• Off-Pump Mini Thoracotomy Versus Sternotomy for Left Anterior Descending Myocardial Bridge Unroofing. The Annals of thoracic surgery Wang, H. n., Pargaonkar, V. S., Hironaka, C. E., Bajaj, S. S., Abbot, C. J., O'Donnell, C. T., Miller, S. L., Honda, Y. n., Rogers, I. S., Tremmel, J. A., Fischbein, M. P., Mitchell, R. S., Schnittger, I. n., Boyd, J. H. 2020

  Abstract

  Myocardial bridge (MB) of the left anterior descending (LAD) coronary artery occurs in approximately 25% of the population. For patients with a symptomatic, hemodynamically significant MB who fail medical therapy, MB unroofing represents the optimal surgical management. Here, we evaluated minimally invasive MB unroofing in selected patients compared with sternotomy.MB unroofing was performed in 141 adult patients via sternotomy on-pump (ST-on, n=40), sternotomy off-pump (ST-off, n=62), or mini thoracotomy off-pump (MT, n=39). Angina symptoms were assessed preoperatively and 6-months postoperatively using the Seattle Angina Questionnaire. Matching included all MT patients and 31 ST-off patients with similar MB characteristics, no previous cardiac surgery or coronary interventions, and no concomitant procedures.MT patients tended to have a shorter MB length than ST-on and ST-off patients (2.57 vs 2.93 vs 3.09 cm, p=0.166). ST-on patients had a longer hospital stay than ST-off and MT patients (5.0 vs 4.0 vs 3.0 days, p<0.001), and more blood transfusions (15.2% vs 0.0% vs 2.6%, p=0.002). After matching, MT patients had a shorter hospital stay than ST-off patients (3.0 vs 4.0 days, p=0.005). No deaths or major complications occurred in any group. In all groups, MB unroofing yielded significant symptomatic improvement regarding physical limitation, angina stability, angina frequency, treatment satisfaction, and quality of life.We report the largest experience of off-pump minimally invasive MB unroofing, which may be safely performed in carefully selected patients, yielding dramatic improvements in angina symptomatology at 6 months after surgery.

  View details for DOI 10.1016/j.athoracsur.2020.11.023

  View details for PubMedID 33333083

• Low Wall Shear Stress Is Associated with Saphenous Vein Graft Stenosis in Patients with Coronary Artery Bypass Grafting. Journal of cardiovascular translational research Khan, M. O., Tran, J. S., Zhu, H. n., Boyd, J. n., Packard, R. R., Karlsberg, R. P., Kahn, A. M., Marsden, A. L. 2020

  Abstract

  Biomechanical forces may play a key role in saphenous vein graft (SVG) disease after coronary artery bypass graft (CABG) surgery. Computed tomography angiography (CTA) of 430 post-CABG patients were evaluated and 15 patients were identified with both stenosed and healthy SVGs for paired analysis. The stenosis was virtually removed, and detailed 3D models were reconstructed to perform patient-specific computational fluid dynamic (CFD) simulations. Models were processed to compute anatomic parameters, and hemodynamic parameters such as local and vessel-averaged wall shear stress (WSS), normalized WSS (WSS*), low shear area (LSA), oscillatory shear index (OSI), and flow rate. WSS* was significantly lower in pre-diseased SVG segments compared to corresponding control segments without disease (1.22 vs. 1.73, p = 0.012) and the area under the ROC curve was 0.71. No differences were observed in vessel-averaged anatomic or hemodynamic parameters between pre-stenosed and control whole SVGs. There are currently no clinically available tools to predict SVG failure post-CABG. CFD modeling has the potential to identify high-risk CABG patients who may benefit from more aggressive medical therapy and closer surveillance. Graphical Abstract.

  View details for DOI 10.1007/s12265-020-09982-7

  View details for PubMedID 32240496

• Women in Thoracic Surgery Scholarship: Impact on Career Path and Interest in Cardiothoracic Surgery. The Annals of thoracic surgery Williams, K. M., Hironaka, C. E., Wang, H. n., Bajaj, S. S., O'Donnell, C. T., Sanchez, M. n., Boyd, J. n., Kane, L. n., Backhus, L. n. 2020

  Abstract

  Women remain underrepresented in Cardiothoracic Surgery (CTS). In 2005, Women in Thoracic Surgery (WTS) began offering scholarships to promote engagement of women in CTS careers. This study explores the effect of WTS scholarships on CTS career milestones.We assessed career development using the number of awardees matching into CTS residency/fellowship, American Board of Thoracic Surgery (ABTS) certification, and academic CTS appointment. Scholarship awardee data were obtained from our WTS database. Comparison data were gathered from the National Residency Match Program and ABTS. Details of the current roles of ABTS certified women were determined from public resources. Qualitative results were gathered from post-scholarship surveys.106 WTS scholarships have been awarded to 38 medical students (MS, 36%), 41 General Surgery residents (GR, 39%), and 27 CTS residents/fellows (CR, 25%). Among MS, 26% of awardees entered integrated CTS residency (vs. <0.1% for medical students, p<0.0001), while 37% entered general surgery residency (vs. 4.8% for medical students, p<0.0001). Of GR awardees, 59% entered CTS fellowships (vs. 7.7% for general surgery residents, p<0.0001), and of CR awardees, 100% earned ABTS certification (vs. 73% ABTS pass rate, p=.01). Of ABTS certified awardees, 44% are practicing CT surgeons at U.S. academic training institutions (vs. 33% of non-awardee ABTS certified women, p=0.419). All awardees reported that their scholarship was valuable in their development.Receipt of a WTS scholarship is associated with successful pursuit of CTS career milestones at significantly higher rates than contemporaries. These scholarships foster a supportive community for women trainees in CTS.

  View details for DOI 10.1016/j.athoracsur.2020.07.020

  View details for PubMedID 32961134

• A Step Back in the Diagnosis and Management of Myocardial Bridging. The Annals of thoracic surgery Schnittger, I., Boyd, J. H., Tremmel, J. A. 2019

  View details for DOI 10.1016/j.athoracsur.2019.09.051

  View details for PubMedID 31706871

• Opioid-Free Ultra-Fast-Track On-Pump Coronary Artery Bypass Grafting Using Erector Spinae Plane Catheters JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Chanowski, E. P., Horn, J., Boyd, J. H., Tsui, B. H., Brodt, J. L. 2019; 33 (7): 1988–90

  View details for DOI 10.1053/j.jvca.2018.10.012

  View details for Web of Science ID 000473249900033

• Impact of Surgical Approach in Double Lung Transplantation: Median Sternotomy Decreases Operative and Cardiopulmonary Bypass Time Compared to Clamshell Thoracotomy Shudo, Y., Rinewalt, D., Lingala, B., Kim, F. Y., He, H., Boyd, J. H., Lee, A. M., Hiesinger, W., Currie, M. E., MacArthur, J. W., Woo, J. ELSEVIER SCIENCE INC. 2019: S414

  View details for DOI 10.1016/j.healun.2019.01.1054

  View details for Web of Science ID 000461365103045

• Utilization of Del Nido Cardioplegia in Adult Coronary Artery Bypass Grafting - A Retrospective Analysis - CIRCULATION JOURNAL O'Donnell, C., Wang, H., Phat Tran, Miller, S., Shuttleworth, P., Boyd, J. H. 2019; 83 (2): 342–46

  View details for DOI 10.1253/circj.CJ-18-0780

  View details for Web of Science ID 000457210100017

• Evaluation of Risk Factors for Heart-Lung Transplant Recipient Outcome: An Analysis of the United Network for Organ Sharing Database. Circulation Shudo, Y. n., Wang, H. n., Lingala, B. n., He, H. n., Kim, F. Y., Hiesinger, W. n., Lee, A. M., Boyd, J. H., Currie, M. n., Woo, Y. J. 2019; 140 (15): 1261–72

  Abstract

  Heart-lung transplantation (HLTx) is an effective treatment for patients with advanced cardiopulmonary failure. However, no large multicenter study has focused on the relationship between donor and recipient risk factors and post-HLTx outcomes. Thus, we investigated this issue using data from the United Network for Organ Sharing database.All adult patients (age ≥18 years) registered in the United Network for Organ Sharing database who underwent HLTx between 1987 and 2017 were included (n=997). We stratified the cohort by patients who were alive without retransplant at 1 year (n=664) and patients who died or underwent retransplant within 1 year of HLTx (n=333). The primary outcome was the influence of donor and recipient characteristics on 1-year post-HLTx recipient death or retransplant. Kaplan-Meier curves were created to assess overall freedom from death or retransplant. To obtain a better effect estimation on hazard and survival time, the parametric Accelerated Failure Time model was chosen to perform time-to-event modeling analyses.Overall graft survival at 1-year post-HLTx was 66.6%. Of donors, 53% were male, and the mean age was 28.2 years. Univariable analysis showed advanced donor age, recipient male sex, recipient creatinine, recipient history of prior cardiac or lung surgery, recipient extracorporeal membrane oxygenation support, transplant year, and transplant center volume were associated with 1-year post-HLTx death or retransplant. On multivariable analysis, advanced donor age (hazard ratio [HR], 1.017; P=0.0007), recipient male sex (HR, 1.701; P=0.0002), recipient extracorporeal membrane oxygenation support (HR, 4.854; P<0.0001), transplant year (HR, 0.962; P<0.0001), and transplantation at low-volume (HR, 1.694) and medium-volume centers (HR, 1.455) in comparison with high-volume centers (P=0.0007) remained as significant predictors of death or retransplant. These predictors were incorporated into an equation capable of estimating the preliminary probability of graft survival at 1-year post-HLTx on the basis of preoperative factors alone.HLTx outcomes may be improved by considering the strong influence of donor age, recipient sex, recipient hemodynamic status, and transplant center volume. Marginal donors and recipients without significant factors contributing to poor post-HLTx outcomes may still be considered for transplantation, potentially with less impact on the risk of early postoperative death or retransplant.

  View details for DOI 10.1161/CIRCULATIONAHA.119.040682

  View details for PubMedID 31589491

• Opioid-Free Ultra-Fast-Track On-Pump Coronary Artery Bypass Grafting Using Erector Spinae Plane Catheters. Journal of cardiothoracic and vascular anesthesia Chanowski, E. J., Horn, J., Boyd, J. H., Tsui, B. C., Brodt, J. L. 2018

  View details for PubMedID 30424939

• Yellow nail syndrome with chylothorax after coronary artery bypass grafting JOURNAL OF CARDIOTHORACIC SURGERY Waliany, S., Chandler, J., Hovsepian, D., Boyd, J., Lui, N. 2018; 13

  View details for DOI 10.1186/s13019-018-0784-8

  View details for Web of Science ID 000445842800001

• Surgical unroofing of hemodynamically significant myocardial bridges in a pediatric population. The Journal of thoracic and cardiovascular surgery Maeda, K., Schnittger, I., Murphy, D. J., Tremmel, J. A., Boyd, J. H., Peng, L., Okada, K., Pargaonkar, V. S., Hanley, F. L., Mitchell, R. S., Rogers, I. S. 2018

  Abstract

  BACKGROUND: Although myocardial bridges (MBs) are traditionally regarded as incidental findings, it has been reported that adult patients with symptomatic MBs refractory to medical therapy benefit from unroofing. However, there is limited literature in the pediatric population. The aim of our study was to evaluate the indications and outcomes for unroofing in pediatric patients.METHODS: We retrospectively reviewed all pediatric patients with MB in our institution who underwent surgical relief. Clinical characteristics, relevant diagnostic data, intraoperative findings, and postoperative outcomes were evaluated.RESULTS: Between 2012 and 2016, 14 pediatric patients underwent surgical unroofing of left anterior descending artery MBs. Thirteen patients had anginal symptoms refractory to medical therapy, and 1 patient was asymptomatic until experiencing aborted sudden cardiac arrest during exercise. Thirteen patients underwent exercise stress echocardiography, all of which showed mid-septal dys-synergy. Coronary computed tomography imaging confirmed the presence of MBs in all patients. Intravascular ultrasound imaging confirmed the length of MBs: 28.2±16.3mm, halo thickness: 0.59±0.24mm, and compression of left anterior descending artery at resting heart rate: 33.0±11.6%. Invasive hemodynamic assessment with dobutamine confirmed the physiologic significance of the MBs with diastolic fractional flow reserve: 0.59±0.13. Unroofing was performed with the patient under cardiopulmonary bypass (CPB) in the initial 9 cases and without CPB in the subsequent 5 cases. All patients were discharged without complications. The 13 symptomatic patients reported resolution of symptoms on follow-up, and improvement in symptoms and quality of life was documented using the Seattle Angina Questionnaire version 7.CONCLUSIONS: Unroofing of MBs can be safely performed in pediatric patients, with or without use of CPB. In symptomatic patients, unroofing can provide relief of symptoms refractory to medical therapy.

  View details for PubMedID 30005887

• Impact of load variations on systolic function of failed left ventricle under extracorporeal membrane oxygenation assessed by strain and tissue doppler imaging Ouazani, N., Shudo, Y., Sallam, K., Lee, A., Boyd, J., Teuteberg, J. WILEY. 2018: 114–15

  View details for Web of Science ID 000434123900311

• How to start a successful robotic mitral surgery program: It's not just about the surgery! JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Wang, H., Boyd, J. H. 2018; 155 (4): 1472–73

  View details for PubMedID 29317089

• MYOCARDIAL BRIDGE MUSCLE INDEX (MMI): A MARKER OF DISEASE SEVERITY AND ITS RELATIONSHIP WITH ENDOTHELIAL DYSFUNCTION AND SYMPTOMATIC OUTCOME IN PATIENTS WITH ANGINA AND A HEMODYNAMICALLY SIGNIFICANT MYOCARDIAL BRIDGE Pargaonkar, V., Schnittger, I., Rogers, I., Tanaka, S., Yamada, R., Kimura, T., Boyd, J., Tremmel, J. ELSEVIER SCIENCE INC. 2018: 160

  View details for DOI 10.1016/S0735-1097(18)30701-0

  View details for Web of Science ID 000429659701010

• Atrial Septal Defect as Unexpected Cause of Pulmonary Artery Hypertension TEXAS HEART INSTITUTE JOURNAL Parikh, R., Boyd, J., Lee, D. P., Witteles, R. 2018; 45 (1): 42–44

  Abstract

  Methamphetamine abuse is an increasingly prevalent cause of pulmonary artery hypertension in the United States. Conversely, an atrial septal defect rarely presents late as pulmonary artery hypertension. We present the case of a 44-year-old methamphetamine abuser who had a 3-month history of worsening fatigue and near-syncope. She had elevated cardiac enzyme levels and right-sided heart strain. Angiographic findings suggested methamphetamine-induced pulmonary artery hypertension; however, we later heard S2 irregularities that raised suspicion of an atrial septal defect. Ultimately, the diagnosis was pulmonary artery hypertension and a large secundum atrial septal defect with left-to-right flow. One year after defect closure, the patient was asymptomatic. In addition to discussing this unexpected case of a secundum atrial septal defect masquerading as methamphetamine-induced pulmonary artery hypertension, we briefly review the natural history of atrial septal defects and emphasize the importance of thorough examination in avoiding diagnostic anchoring bias.

  View details for DOI 10.14503/THIJ-17-6208

  View details for Web of Science ID 000426402700011

  View details for PubMedID 29556152

  View details for PubMedCentralID PMC5832086

• Second Arterial Versus Venous Conduits for Multivessel Coronary Artery Bypass Surgery in California. Circulation Goldstone, A. B., Chiu, P. n., Baiocchi, M. n., Wang, H. n., Lingala, B. n., Boyd, J. H., Woo, Y. J. 2018; 137 (16): 1698–1707

  Abstract

  Whether a second arterial conduit improves outcomes after multivessel coronary artery bypass grafting remains unclear. Consequently, arterial conduits other than the left internal thoracic artery are seldom used in the United States.Using a state-maintained clinical registry including all 126 nonfederal hospitals in California, we compared all-cause mortality and rates of stroke, myocardial infarction, repeat revascularization, and sternal wound infection between propensity score-matched cohorts who underwent primary, isolated multivessel coronary artery bypass grafting with the left internal thoracic artery, and who received a second arterial conduit (right internal thoracic artery or radial artery, n=5866) or a venous conduit (n=53 566) between 2006 and 2011. Propensity score matching using 34 preoperative characteristics yielded 5813 matched sets. A subgroup analysis compared outcomes between propensity score-matched recipients of a right internal thoracic artery (n=1576) or a radial artery (n=4290).Second arterial conduit use decreased from 10.7% in 2006 to 9.1% in 2011 (P<0.0001). However, receipt of a second arterial conduit was associated with significantly lower mortality (13.1% versus 10.6% at 7 years; hazard ratio, 0.79; 95% confidence interval [CI], 0.72-0.87), and lower risks of myocardial infarction (hazard ratio, 0.78; 95% CI, 0.70-0.87) and repeat revascularization (hazard ratio, 0.82; 95% CI, 0.76-0.88). In comparison with radial artery grafts, right internal thoracic artery grafts were associated with similar mortality rates (right internal thoracic artery 10.3% versus radial artery 10.7% at 7 years; hazard ratio, 1.10; 95% CI, 0.89-1.37) and individual risks of cardiovascular events, but the risk of sternal wound infection was increased (risk difference, 1.07%; 95% CI, 0.15-2.07).Second arterial conduit use in California is low and declining, but arterial grafts were associated with significantly lower mortality and fewer cardiovascular events. A right internal thoracic artery graft offered no benefit over that of a radial artery, but did increase risk of sternal wound infection. These findings suggest surgeons should consider lowering their threshold for using arterial grafts, and the radial artery may be the preferred second conduit.

  View details for PubMedID 29242351

• The tip of the iceberg: Evaluating the mechanism behind dehiscence of mitral annuloplasty rings JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY MacArthur, J. W., Boyd, J. 2018; 155 (1): 140–41

  View details for DOI 10.1016/j.jtcvs.2017.08.099

  View details for Web of Science ID 000422751300058

• Methodological Standards for Meta-Analyses and Qualitative Systematic Reviews of Cardiac Prevention and Treatment Studies A Scientific Statement From the American Heart Association CIRCULATION Rao, G., Lopez-Jimenez, F., Boyd, J., D'Amico, F., Durant, N. H., Hlatky, M. A., Howard, G., Kirley, K., Masi, C., Powell-Wiley, T. M., Solomonides, A. E., West, C. P., Wessel, J., Amer Heart Assoc Council Lifestyle, Council Cardiovasc Stroke Nursing, Council Cardiovasc Surg Anesthesia, Council Clinical Cardiology, Council Functional Genomics, Stroke Council 2017; 136 (10): E172-+

  Abstract

  Meta-analyses are becoming increasingly popular, especially in the fields of cardiovascular disease prevention and treatment. They are often considered to be a reliable source of evidence for making healthcare decisions. Unfortunately, problems among meta-analyses such as the misapplication and misinterpretation of statistical methods and tests are long-standing and widespread. The purposes of this statement are to review key steps in the development of a meta-analysis and to provide recommendations that will be useful for carrying out meta-analyses and for readers and journal editors, who must interpret the findings and gauge methodological quality. To make the statement practical and accessible, detailed descriptions of statistical methods have been omitted. Based on a survey of cardiovascular meta-analyses, published literature on methodology, expert consultation, and consensus among the writing group, key recommendations are provided. Recommendations reinforce several current practices, including protocol registration; comprehensive search strategies; methods for data extraction and abstraction; methods for identifying, measuring, and dealing with heterogeneity; and statistical methods for pooling results. Other practices should be discontinued, including the use of levels of evidence and evidence hierarchies to gauge the value and impact of different study designs (including meta-analyses) and the use of structured tools to assess the quality of studies to be included in a meta-analysis. We also recommend choosing a pooling model for conventional meta-analyses (fixed effect or random effects) on the basis of clinical and methodological similarities among studies to be included, rather than the results of a test for statistical heterogeneity.

  View details for DOI 10.1161/CIR.0000000000000523

  View details for Web of Science ID 000409164500001

  View details for PubMedID 28784624

• Tricuspid leaflet repair: innovative solutions ANNALS OF CARDIOTHORACIC SURGERY Boyd, J. H., Edelman, J. B., Scoville, D. H., Woo, Y. 2017; 6 (3): 248–54

  Abstract

  Tricuspid regurgitation (TR) represents a significant disease process and when severe, is associated with increased mortality. Recent guidelines support a more aggressive approach to tricuspid valve (TV) surgery, especially when encountered with left-sided valvular pathology. While annuloplasty has been the standard treatment for TR, it may not provide as effective or durable a repair compared to annuloplasty combined with TV repair techniques. Several of these approaches are discussed including bicuspidalization, anterior leaflet augmentation, edge to edge repair, neochords, leaflet resection and combined approaches. Although patient cohorts in most of the studies examining these techniques are small, the long-term durability of TV repair is significant.

  View details for PubMedID 28706867

• Effect of Broader Geographic Sharing of Donor Lungs on Regional Waitlist (WL) Mortality and Transplant Center Volume Mooney, J., Chhatwani, L., Boyd, J., Dhillon, G. S. ELSEVIER SCIENCE INC. 2017: S206–S207

  View details for Web of Science ID 000398839800528

• Surgical Strategy to Support Right Ventricle with HVAD RVAD: Right Atrial vs Right Ventricular Diaphragmatic Surface Cannulation Shudo, Y., Ha, R. V., Reinhartz, O., Woo, J., Boyd, J., Almond, C., Rosenthal, D. N., Chen, S., Maeda, K. ELSEVIER SCIENCE INC. 2017: S29

  View details for Web of Science ID 000398839800054

• WHOLE HEART OF THE MATTER Parikh, R., Boyd, J., Lee, D., Witteles, R. ELSEVIER SCIENCE INC. 2017: 2411

  View details for Web of Science ID 000397342303333

• EFFECTIVENESS OF A SECOND ARTERIAL CONDUIT FOR MULTI VESSEL CORONARY BYPASS: A STATE-WIDE ANALYSIS OF 60,897 PATIENTS Goldstone, A. B., Chiu, P., Baiocchi, M., Ligala, B., Boyd, J., Woo, Y. ELSEVIER SCIENCE INC. 2017: 26

  View details for Web of Science ID 000397342300027

• Current status of domino heart transplantation. Journal of cardiac surgery Shudo, Y., Ma, M., Boyd, J. H., Woo, Y. J. 2017; 32 (3): 229-232

  Abstract

  Domino heart transplant, wherein the explanted heart from the recipient of an en-bloc heart-lung is utilized for a second recipient, represents a unique surgical strategy for patients with end-stage heart failure. With a better understanding of the potential advantages and disadvantages of this procedure, its selective use in the current era can improve and maximize organ allocation in the United States. In this report, we reviewed the current status of domino heart transplantation.

  View details for DOI 10.1111/jocs.13104

  View details for PubMedID 28219115

• Successful use of donor lungs after repairing severely injured pulmonary vein of donor lungs. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery Shudo, Y. n., Miller, S. L., Boyd, J. H., Woo, Y. J. 2017

  View details for PubMedID 29186381

• Prior, proper planning prevents poor performance JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Boyd, J. H. 2016; 152 (6): E143

  View details for PubMedID 27640949

• Surgical Unroofing of Hemodynamically Significant Left Anterior Descending Myocardial Bridges. Annals of thoracic surgery Boyd, J. H., Pargaonkar, V. S., Scoville, D. H., Rogers, I. S., Kimura, T., Tanaka, S., Yamada, R., Fischbein, M. P., Tremmel, J. A., Mitchell, R. S., Schnittger, I. 2016

  Abstract

  Left anterior descending artery myocardial bridges (MBs) range from clinically insignificant incidental angiographic findings to a potential cause of sudden cardiac death. Within this spectrum, a group of patients with isolated, symptomatic, and hemodynamically significant MBs despite maximally tolerated medical therapy exist for whom the optimal treatment is controversial. We evaluated supraarterial myotomy, or surgical unroofing, of the left anterior descending MBs as an isolated procedure in these patients.In 50 adult patients, we prospectively evaluated baseline clinical characteristics, risk factors, and medications for coronary artery disease, relevant diagnostic data (stress echocardiography, computed tomography angiography, stress coronary angiogram with dobutamine challenge for measurement of diastolic fractional flow reserve, and intravascular ultrasonography), and anginal symptoms using the Seattle Angina Questionnaire. These patients then underwent surgical unroofing of their left anterior descending artery MBs followed by readministration of the Seattle Angina Questionnaire at 6.6-month (range, 2 to 13) follow-up after surgery.Dramatic improvements were noted in physical limitation due to angina (52.0 versus 87.1, p < 0.001), anginal stability (29.6 versus 66.4, p < 0.001), anginal frequency (52.1 versus 84.7, p < 0.001), treatment satisfaction (76.1 versus 93.9, p < 0.001), and quality of life (25.0 versus 78.9, p < 0.001), all five dimensions of the Seattle Angina Questionnaire. There were no major complications or deaths.Surgical unroofing of carefully selected patients with MBs can be performed safely as an independent procedure with significant improvement in symptoms postoperatively. It is the optimal treatment for isolated, symptomatic, and hemodynamically significant MBs resistant to maximally tolerated medical therapy.

  View details for DOI 10.1016/j.athoracsur.2016.08.035

  View details for PubMedID 27745841

• Successful Operative Repair of Delayed Left Ventricle Rupture From Blunt Trauma. Annals of thoracic surgery Greene, C. L., Boyd, J. H. 2016; 102 (2): e101-3

  Abstract

  A 21-year-old female was found to have an enlarging pericardial effusion 10 days after a 40-foot fall. Initial cardiac evaluation was negative. Ten days after presentation she developed hemodynamic compromise and chest computed tomography was concerning for cardiac rupture. The patient was taken to the operating room where the ruptured posterior ventricle was repaired, perforation in the P1 leaflet was identified and the mitral valve was replaced. The patient survived. To our knowledge, this is the first report of survival after delayed presentation of atrioventricular rupture at the level of the mitral valve.

  View details for DOI 10.1016/j.athoracsur.2016.01.031

  View details for PubMedID 27449439

• A tale of 2 treatments: The best of times or the worst of times? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Boyd, J. H. 2016; 152 (1): 137–38

  View details for PubMedID 27130302

• Effect of Transplant Center Volume on Cost and Readmissions in Medicare Lung Transplant Recipients. Annals of the American Thoracic Society Mooney, J. J., Weill, D., Boyd, J. H., Nicolls, M. R., Bhattacharya, J., Dhillon, G. S. 2016; 13 (7): 1034-1041

  Abstract

  While lung transplant recipient survival is better at higher volume centers, the effect of center volume on admission cost and early hospital readmission is unknown.To understand the association between transplant center volume and recipient risk-adjusted transplant admission cost, in-hospital mortality, and early hospital readmission in lung transplant recipients.Medicare lung transplant recipients from May 4, 2005 to December 31, 2011 were identified through linkage of transplant registry and Medicare administrative claims. Transplant admission cost was extracted, adjusted for regional price variation, and compared across low, intermediate, and high volume centers. A multivariable hierarchical generalized linear regression model was used to assess the effect of transplant center volume on recipient adjusted cost. Modified Poisson regression models were used to assess adjusted in-hospital mortality and early hospital readmission by transplant center volume.There were 3,128 Medicare lung transplant recipients identified. Unadjusted transplant cost was lower at high volume centers (mean $131,352, SD±$106,165; median $90,177, IQR $79,165-$137,915) than intermediate (mean $138,792, SD±$106,270; median $93,024, IQR $82,700-$154,857) or low volume (mean $143,609, SD±$123,316; median $95,234, IQR $83,052-$152,149) centers (p<0.0001). After adjusting for recipient health risk, low volume centers had an 11.66% greater transplant admission cost (p=0.040), a 41% greater risk for in-hospital mortality (p=0.015), and a 14% greater risk for early hospital readmission (p=0.033) compared to high volume centers. There was no significant difference in transplant cost, in-hospital mortality, or early hospital readmission between intermediate and high volume centers.Lung transplant admission cost, in-hospital mortality, and early hospital readmission rate are lower at high volume centers compared to low volume centers.

  View details for DOI 10.1513/AnnalsATS.201601-017OC

  View details for PubMedID 27064753

• Salvage Extracorporeal Membrane Oxygenation Prior to "Bridge" Transcatheter Aortic Valve Replacement. Journal of cardiac surgery Chiu, P., Fearon, W. F., Raleigh, L. A., Burdon, G., Rao, V., Boyd, J. H., Yeung, A. C., Miller, D. C., Fischbein, M. P. 2016; 31 (6): 403-405

  Abstract

  We describe a patient who presented in profound cardiogenic shock due to bioprosthetic aortic valve stenosis requiring salvage Extracorporeal Membrane Oxygenation followed by a "bridge" valve-in-valve transcatheter aortic valve replacement. doi: 10.1111/jocs.12750 (J Card Surg 2016;31:403-405).

  View details for DOI 10.1111/jocs.12750

  View details for PubMedID 27109017

• EFFECT OF SURGICAL UNROOFING OF A MYOCARDIAL BRIDGE ON EXERCISE INDUCED QT INTERVAL DISPERSION AND ANGINAL SYMPTOMS IN PATIENTS WITH ANGINA IN THE ABSENCE OF OBSTRUCTIVE CORONARY ARTERY DISEASE Pargaonkar, V., Nishikii, M., Boyd, J., Rogers, I., Schnittger, I., Tremmel, J. ELSEVIER SCIENCE INC. 2016: 2150

  View details for DOI 10.1016/S0735-1097(16)32151-9

  View details for Web of Science ID 000375188702996

• Bilateral Giant Coronary Artery Aneurysms Complicated by Acute Coronary Syndrome and Cardiogenic Shock. Annals of thoracic surgery Chiu, P., Lynch, D., Jahanayar, J., Rogers, I. S., Tremmel, J., Boyd, J. 2016; 101 (4): e95-7

  Abstract

  Giant coronary aneurysms are rare. We present a 25-year-old woman with a known history of non-Kawasaki/nonatherosclerotic bilateral coronary aneurysms. She was transferred to our facility with acute coronary syndrome complicated by cardiogenic shock. Angiography demonstrated giant bilateral coronary aneurysms and complete occlusion of the left anterior descending (LAD) artery. Emergent coronary artery bypass grafting was performed. Coronary artery bypass grafting is the preferred approach for addressing giant coronary aneurysms. Intervention on the aneurysm varies in the literature. Aggressive revascularization is recommended in the non-Kawasaki/nonatherosclerotic aneurysm patient, and ligation should be performed in patients with thromboembolic phenomena.

  View details for DOI 10.1016/j.athoracsur.2015.06.104

  View details for PubMedID 27000621

• FFR 4 CABG: More than a vanity plate JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Boyd, J. H. 2016; 151 (4): 933–34

  View details for PubMedID 26809424

• A novel approach to ischemic mitral regurgitation (IMR). Annals of cardiothoracic surgery Scoville, D. H., Boyd, J. B. 2015; 4 (5): 443-448

  Abstract

  Ischemic mitral regurgitation (IMR) is a complicated medical condition with varying degrees of coronary artery disease and mitral regurgitation (MR). The traditional surgical treatment option for those with indications for intervention is coronary artery bypass grafting (CABG) plus or minus mitral valve repair or replacement (MVR). Percutaneous coronary intervention, hybrid coronary revascularization (HCR), and conventional CABG are three techniques available to address coronary artery disease (CAD). Percutaneous edge-to-edge repair, minimally invasive, and traditional sternotomy are accepted approaches for the treatment of MR. When taken in combination, there are nine methods available to revascularize the myocardium and restore competency to the mitral valve. While most of these treatment options have not been studied in detail, they may offer novel solutions to a widely variable and complex IMR patient population. Thus, a comparative analysis including an examination of potential benefits and risks will be helpful and potentially allow for more patient-specific treatment strategies.

  View details for DOI 10.3978/j.issn.2225-319X.2015.08.06

  View details for PubMedID 26539349

  View details for PubMedCentralID PMC4598475

• Ventricular assist device implantation in the elderly. Annals of cardiothoracic surgery Hiesinger, W., Boyd, J. H., Woo, Y. J. 2014; 3 (6): 570-572

  Abstract

  Dramatic advances in ventricular assist device (VAD) design and patient management have made mechanical circulatory support an attractive therapeutic option for the growing pool of elderly heart failure patients.A literature review of all relevant studies was performed. No time or language restrictions were imposed, and references of the selected studies were checked for additional relevant citations.In concordance with the universal trend in mechanical circulatory support, continuous flow devices appear to have particular benefits in the elderly. In addition, the literature suggests that early intervention before the development of cardiogenic shock, important in all patients, is particularly paramount in older patients.The ongoing refinement of patient selection, surgical technique, and post-operative care will continue to improve surgical outcomes, and absolute age may become a less pivotal criterion for mechanical circulatory support. However, clear guidelines for the use of mechanical circulatory support in the elderly remain undefined.

  View details for DOI 10.3978/j.issn.2225-319X.2014.09.07

  View details for PubMedID 25512896

• Human aortic allograft: an excellent conduit choice for superior vena cava reconstruction JOURNAL OF CARDIOTHORACIC SURGERY Spera, K., Kesler, K. A., Syed, A., Boyd, J. H. 2014; 9

  Abstract

  Superior vena cava (SVC) reconstruction is occasionally required in the treatment of benign and malignant conditions. We report a patient with symptomatic SVC obstruction secondary to mediastinal fibrosis successfully reconstructed with an aortic allograft.

  View details for DOI 10.1186/1749-8090-9-16

  View details for Web of Science ID 000331888700001

  View details for PubMedID 24428914

• Epicardial adipose excision slows the progression of porcine coronary atherosclerosis JOURNAL OF CARDIOTHORACIC SURGERY Mckenney, M. L., Schultz, K. A., Boyd, J. H., Byrd, J. P., Alloosh, M., Teague, S. D., Arce-Esquivel, A. A., Fain, J. N., Laughlin, M. H., Sacks, H. S., Sturek, M. 2014; 9

  Abstract

  In humans there is a positive association between epicardial adipose tissue (EAT) volume and coronary atherosclerosis (CAD) burden. We tested the hypothesis that EAT contributes locally to CAD in a pig model.Ossabaw miniature swine (n=9) were fed an atherogenic diet for 6 months to produce CAD. A 15 mm length by 3-5 mm width coronary EAT (cEAT) resection was performed over the middle segment of the left anterior descending artery (LAD) 15 mm distal to the left main bifurcation. Pigs recovered for 3 months on atherogenic diet. Intravascular ultrasound (IVUS) was performed in the LAD to quantify atheroma immediately after adipectomy and was repeated after recovery before sacrifice. Coronary wall biopsies were stained immunohistochemically for atherosclerosis markers and cytokines and cEAT was assayed for atherosclerosis-related genes by RT-PCR. Total EAT volume was measured by non-contrast CT before each IVUS.Circumferential plaque length increased (p<0.05) in the proximal and distal LAD segments from baseline until sacrifice whereas plaque length in the middle LAD segment underneath the adipectomy site did not increase. T-cadherin, scavenger receptor A and adiponectin were reduced in the intramural middle LAD. Relative to control pigs without CAD, 11β-hydroxysteroid dehydrogenase (11βHSD-1), CCL19, CCL21, prostaglandin D2 synthase, gp91phox [NADPH oxidase], VEGF, VEGFGR1, and angiotensinogen mRNAs were up-regulated in cEAT. EAT volume increased over 3 months.In pigs used as their own controls, resection of cEAT decreased the progression of CAD, suggesting that cEAT may exacerbate coronary atherosclerosis.

  View details for DOI 10.1186/1749-8090-9-2

  View details for Web of Science ID 000331886200002

  View details for PubMedID 24387639

• Ischemic Mitral Regurgitation - Where Do We Stand? CIRCULATION JOURNAL Boyd, J. H. 2013; 77 (8): 1952-1956

  Abstract

  Chronic ischemic mitral regurgitation (IMR) is still a significant clinical problem. It is present in 10-20% of patients with coronary artery disease and is associated with a worse prognosis after myocardial infarction and subsequent revascularization. Currently, coronary artery bypass grafting combined with restrictive annuloplasty is the most commonly performed surgical procedure, although novel approaches have been used in limited numbers with varying degrees of success. The purpose of this review is to clarify the rationale for the surgical techniques applicable to IMR. In order to do so, the condition will be defined and the evolution of classic or traditional surgical approaches to repairing or replacing the mitral valve in the setting of IMR will be described. Finally, novel approaches to the repair of the ischemic mitral valve will be considered. 

  View details for DOI 10.1253/circj.CJ-13-0743

  View details for Web of Science ID 000322752000004

  View details for PubMedID 23877709

• Neonatal cavopulmonary assist: Pulsatile versus steady-flow pulmonary perfusion ANNALS OF THORACIC SURGERY Myers, C. D., Boyd, J. H., Presson, R. G., Vijay, P., COATS, A. C., Brown, J. W., Rodefeld, M. D. 2006; 81 (1): 257-263

  Abstract

  Morbidity and mortality associated with single-ventricle physiology decrease substantially once a systemic venous, rather than systemic arterial, source of pulmonary blood flow is established. Cavopulmonary assist has potential to eliminate critical dependence on the problematic systemic-to-pulmonary shunt as a source of pulmonary blood flow in neonates. We have previously demonstrated feasibility of neonatal cavopulmonary assist under steady-flow conditions. We hypothesized that pulsatile pulmonary perfusion would further improve pulmonary hemodynamics.Lambs (weight 7.2 +/- 1.1 kg, age 7.9 +/- 1.5 days) underwent total cavopulmonary diversion using bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to augment cavopulmonary flow. Pulsatility was created with an intermittently compressed compliance chamber in the circuit. Hemodynamic and gas exchange data were measured for 8 hours. Pulsatile (n = 6), steady-flow (n = 13), and control (n = 6) groups were compared using two-way analysis of variance with repeated measures.All animals remained physiologically stable with normal gas exchange function. Mean pulmonary arterial pressure was elevated in pulsatile and steady-flow groups compared with the control group and within-group baseline values. Pulmonary vascular resistance was elevated initially in both assist groups but decreased significantly over the last 4 hours of the study and normalized after hour 4 in the pulsatile perfusion group. Pulmonary vascular resistance also normalized to control in the steady-flow group after hour 7.Both steady-flow and pulsatile pulmonary perfusion demonstrated normalization of pulmonary vascular resistance to control in a neonatal model of univentricular Fontan circulation. These results suggest that there is no benefit to pulsatile flow in this model.

  View details for DOI 10.1016/j.athoracsur.2005.07.003

  View details for Web of Science ID 000234585400037

  View details for PubMedID 16368377

• Cavopulmonary assist in the neonate: An alternative strategy for single-ventricle palliation 29th Annual Meeting of the Western-Thoracic-Surgical-Association Rodefeld, M. D., Boyd, J. H., Myers, C. D., Presson, R. G., Wagner, W. W., Brown, J. W. MOSBY-ELSEVIER. 2004: 705–11

  Abstract

  Cavopulmonary blood flow, rather than a systemic arterial source of pulmonary blood flow, stabilizes Norwood physiology. We hypothesized that pump-assisted cavopulmonary diversion would yield stable pulmonary and systemic hemodynamics in the neonate. This was tested in a newborn animal model of total cavopulmonary diversion and univentricular Fontan circulation.Lambs (n = 13; mean weight, 5.6 +/- 1.5 kg; mean age, 6.8 +/- 4.0 days) were anesthetized and mechanically ventilated. Baseline hemodynamic parameters were measured. Total cavopulmonary diversion was performed with bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to assist cavopulmonary flow. Support was titrated to normal physiologic parameters. Hemodynamic data, arterial blood gases, and lactate values were measured for 8 hours. Baseline, 1-hour, and 8-hour time points were compared by using analysis of variance.All animals remained stable without the use of volume loading, inotropic support, or pulmonary vasodilator therapy. Cardiac index, systemic arterial pressure, left atrial pressure, and lactate values were similar to baseline values 8 hours after surgery. Mean pulmonary arterial pressure and pulmonary vascular resistance were modestly increased 8 hours after surgery. Mean arterial pH, Po(2), and Pco(2) values remained stable throughout the study.Cavopulmonary assist is feasible in a neonatal animal model of total cavopulmonary diversion and univentricular Fontan circulation with acceptable pulmonary arterial pressures and without altering regional volume distribution or cardiac output. Pump-assisted cavopulmonary diversion, in combination with Norwood aortic arch reconstruction, could solve several major problems associated with a systemic shunt-dependent univentricular circulation, including hypoxemia, impaired diastolic coronary perfusion, and ventricular volume overload.

  View details for DOI 10.1016/j.jtcvs.2003.11.007

  View details for Web of Science ID 000220115400017

  View details for PubMedID 15001898

• Cavopulmonary assist: Circulatory support for the univentricular Fontan circulation 39th Annual Meeting of the Society-of-Thoracic-Surgeons Rodefeld, M. D., Boyd, J. H., Myers, C. D., LaLone, B. J., Bezruczko, A. J., Potter, A. W., Brown, J. W. ELSEVIER SCIENCE INC. 2003: 1911–16

  Abstract

  Following Fontan palliation, the univentricular circulation is notable for coexisting systemic venous hypertension and pulmonary arterial hypotension. Assisted cavopulmonary blood flow to overcome this pressure gradient would restore the circulation to one more closely resembling normal two-ventricle physiology. We hypothesized that mechanical augmentation of cavopulmonary blood flow would provide physiologic stability in a model of cavopulmonary diversion and univentricular circulation.Yearling sheep (n = 13, mean weight 56.5 kg) underwent total cavopulmonary diversion on cardiopulmonary bypass. The superior and inferior vena cavae were anastomosed directly to the right pulmonary artery. Axial flow pumps were positioned within both vena cavae to assist blood flow from the systemic venous circulation into the pulmonary vasculature. Baseline ventilation was resumed, cardiopulmonary bypass was weaned, and pump support was titrated to obtain normal physiologic measurement. Cardiopulmonary data were collected for 6 hours.All animals demonstrated hemodynamic stability without need for volume loading, inotropic support, or pulmonary vasodilator therapy. Cardiac output, pulmonary vascular resistance, pulmonary arterial pressure, inferior vena caval pressure, and arterial pCO(2) and pO(2) values 6 hours after intervention were similar to baseline values. Arterial lactate levels steadily decreased throughout the cavopulmonary assist period.Cavopulmonary assist with a percutaneous pump provides physiologic stability in a model of total cavopulmonary diversion and univentricular Fontan circulation without altering regional volume distribution or cardiac output. This mode of circulatory support may have potential to benefit patients with marginal Fontan hemodynamics in both the early and late time periods.

  View details for DOI 10.1016/S0003-4975(03)01014-2

  View details for Web of Science ID 000186986500028

  View details for PubMedID 14667610